The Mind's Malfunction and Repair: Psychiatry as Causal Detective Work

At four in the morning, the psychiatric consultation desk lights up with three pagers at once. A 28-year-old woman on the ward keeps ripping off her hospital wristband and threatening to jump from the roof — five minutes ago she idealized the head nurse, and now she is calling her "garbage." A 65-year-old man, three days into alcohol withdrawal, is shaking all over and sees nonexistent insects crawling up the wall. A 16-year-old boy, a survivor of a car accident six months ago, has this month begun suffering insomnia, nightmares, and a startle response to the faintest sound.

At first glance these are three entirely different illnesses. But once you understand the language of psychiatry, you will see they are all asking the same question — which neural circuit has been knocked out of balance? Too much dopamine produces hallucinations, too little produces blunted affect; too little serotonin produces depression, too much produces clonus and fever; a runaway amygdala is anxiety, and a hippocampus locked down by alcohol's action on NMDA receptors is a blackout. The licensing exam's psychiatry section is both maddening and mesmerizing for the same reason: it never asks you to memorize a lookup table matching symptom to diagnosis. It asks you to work like a detective — from a single clinical picture, a single lab value, a single drug side effect, to reason backward to the circuit that has been interrupted.

This entire issue runs on a single line of reasoning: work out first which neurotransmitter, which circuit, and which developmental stage has gone wrong, and the symptoms, diagnostic timeline, and medication sequence will surface on their own. We begin at the two ends of the age spectrum — children and the elderly — then walk through the dopamine storm of schizophrenia, cross into the monoamine circuits of mood and anxiety, run headlong into the twin emergencies of substances and psychiatric drugs, and finally come to rest in those "borderlands of the mind": somatic symptoms, personality, eating, and ethics. The must-know points at the end of every section grow naturally out of the causal chain that precedes them.

1. The Two Ends of Life: The Child's Brain and the Aging Brain

To cut cleanly between child and geriatric psychiatry, keep one shared question in mind: which direction is this brain traveling? In a brain still developing upward, the problem is a circuit burning too bright (the excess dopamine of Tourette syndrome) or a threshold never cleared (the executive-function deficits of ADHD). In a brain traveling downward into decline, the problem is a circuit going dark (falling acetylcholine in Alzheimer disease, AD), or one region dimming earlier than the rest (the frontal lobe failing first in frontotemporal dementia, FTD). Once the direction is clear, half the question answers itself.

ADHD: Unless All Three Locks Open, None of Them Count

🔬 Mechanism, unpacked

ADHD is the textbook neurodevelopmental disorder. Laid out as a causal chain: genetics + environmental insult → weakened DA/NE signaling in the prefrontal cortex → executive-function deficits (inhibition, attention, working memory) → cross-situational inattention and hyperactive-impulsive behavior → academic/social impairment. Because it is "developmental" rather than "reactive," the symptoms must be present since childhood, must appear across settings, and must cause functional impairment — three requirements that are really three locks cut from the same causal chain. Trap: assuming the DSM-IV cutoff of "before age 7" is still the current standard (it has been changed to before age 12); assuming symptoms confined to school alone qualify as ADHD (they do not — at least 2 settings are required).

Requirement	Current DSM-5	Outdated trap
Age of onset	Symptoms present before age 12	Old DSM-IV "before age 7"
Number of settings	Present in ≥2 settings (home, school, etc.)	"Only one setting" is enough
Symptom cluster	Inattentive +/or hyperactive-impulsive	—
Functioning	Must cause social/academic/occupational impairment	Symptoms without impairment

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

First-line treatment is central stimulants (methylphenidate, amphetamine-class agents) — the logic is direct: if prefrontal dopamine is deficient, push it up. Non-stimulant alternatives are atomoxetine (an NRI) and α2 agonists (clonidine, guanfacine), reserved for patients who cannot tolerate stimulants, who have tics, or where abuse potential is a concern. Two frequently tested myths need debunking: stimulants do transiently suppress growth velocity, reduce appetite, and disturb sleep onset — that part is true — but "stimulants must worsen tics and are therefore absolutely contraindicated" is outdated thinking; most patients with comorbid tics can still use them safely.

Tourette Syndrome: Too Much Dopamine, So Antagonize It

Drug direction	Examples	Effect on tics	Why
D2 antagonists	haloperidol, pimozide, risperidone, aripiprazole	Improve	Block excess dopamine
α2 agonists	clonidine, guanfacine	Improve (especially with comorbid ADHD)	Fewer side effects, common first line
Dopamine agonist	—	Worsens	Fuel on the fire

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Heritability is high, with a higher concordance rate in monozygotic than dizygotic twins. Traditional question banks describe it as "autosomal dominant with incomplete penetrance"; the modern view leans toward complex polygenic inheritance, but if the exam poses this question it typically still expects the old answer.

ASD: Which Treatments "Work" and Which Just "Sound Reasonable"

Autism spectrum disorder (ASD) is defined at its core by deficits in social-emotional reciprocity plus restricted, repetitive behaviors, and it is a neurodevelopmental disorder. What the licensing exam tests over and over is not the symptoms but the treatment — it loves slipping in options that "sound reasonable" but lack RCT evidence. Evidence-based options are ABA (applied behavior analysis), early intensive behavioral intervention, and speech therapy; CBT is also effective for comorbid anxiety/depression/OCD. Lacking high-quality RCT evidence is sensory integration therapy for the core symptoms of ASD — this is the most commonly missed trap, because the name sounds exactly right.

The real trap in ASD is "sensory integration works on core symptoms" — it sounds the most reasonable, but no high-quality RCT backs it up.

The Age Myth in Conduct Disorder

Conduct disorder is not a "pediatric-only" diagnosis. DSM-5 does not restrict it to patients under 18 — past age 18, if criteria are still met and the threshold for antisocial personality disorder (ASPD) has not been reached, conduct disorder can still be diagnosed, and the two are not diagnosed together (an adult meeting ASPD criteria is diagnosed with ASPD instead). Conduct disorder is a precursor to ASPD, but the diagnosis does not automatically switch over on someone's eighteenth birthday.

Normal Aging: Every Neurotransmitter Moves in the Same Direction — Down

The aging brain does not lose just one transmitter. DA, ACh, NE, and 5-HT all decline, along with cerebral blood flow and oxygen utilization, while IQ — buoyed by relatively preserved crystallized intelligence — can remain stable to about age 80. The exam loves reversing this direction: "NE increases with normal aging" is a trap — cross it out on sight.

Item	Change	Key point
Dopamine (DA)	↓	—
Acetylcholine (ACh)	↓	Most closely linked to cognitive decline
Norepinephrine (NE)	↓	Written as "increased" = wrong answer
Serotonin (5-HT)	↓	—
Cerebral blood flow/O₂ utilization	↓	—

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

A few numbers worth memorizing: the prevalence of late-life depression is about 15%; arthritis is the most common cause of disability in the elderly (disability ≠ dementia); persecutory delusions are the most common type of late-onset delusional disorder; new-onset psychotic symptoms in the elderly usually respond to low-dose antipsychotics — "poor response" is a reverse trap, though EPS and falls warrant caution.

Differentiating Dementias: FTD Is "The Person Changed," AD Is "The Facts Are Forgotten"

Feature	Frontotemporal dementia (FTD)	Alzheimer disease (AD)
Early core feature	Personality/behavior change, language impairment	Memory impairment (especially recent memory)
Social cognition	Markedly impaired early	Relatively preserved early
Learning and memory	Relatively preserved early	Impaired early
Age of onset	Earlier, often <65 years	Later

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

FTD is "the person changed" (behavior/social skills fail first); AD is "the facts are forgotten" (memory fails first).

Remember this one line and every comparison question answers itself. FTD's "early impairment of social cognition" is the pit that reverse traps love to dig — if a question states "FTD preserves social cognition relatively well early on," that statement is false.

♪ Sing-along text — English rendering of the Mandarin song lyrics

A third-grade boy cannot stop moving in the exam room, sliding off his chair onto the floor and then climbing onto his mother's lap; his teacher at school complains that he cannot pay attention and blurts out in class. Across the waiting room sits a seventy-eight-year-old man; his wife says he has become a different person over the past six months — once meticulous and considerate, he now screams at store clerks at the supermarket, insists he has not eaten moments after finishing a meal, and has started taking off his pants in public. One is a developing brain with every door thrown open; the other is a degenerating brain going dark room by room. The two ends of the age spectrum in psychiatry are the pairing the licensing exam loves most to place side by side on the same page.

In the developing brain, watch which circuit burns too bright; in the aging brain, watch which light goes dark first — get the direction straight, and the symptoms line themselves up.

To understand ADHD, start back at the prefrontal cortex. Its essence is prefrontal executive-function deficiency: dopamine and norepinephrine signaling in the prefrontal cortex runs weak, so the child cannot sustain impulse inhibition or maintain attention. Because it is a developmental problem, the symptoms must be present since childhood and cannot first appear in adulthood; and because it is a whole-brain regulatory problem, it cannot occur in only one setting — it must show up across settings. Finally, an inability to sit still can just be a personality trait; only when it causes social, academic, or occupational impairment does it graduate into a disorder. So behind the three locks lies a single causal chain — just remember before age 12, two settings, functional impairment. The old "before age 7" cutoff is the outdated distractor the exam loves to dangle; symptoms confined to school, or onset in middle school, cannot be diagnosed unless all three locks open together. Medication follows the same mechanism: since prefrontal dopamine is deficient, central stimulants push it up, with methylphenidate and amphetamine-class agents working best; for patients who cannot tolerate stimulants, who have tics, or where abuse potential is a concern, switch to atomoxetine, a norepinephrine reuptake inhibitor, or to α2 agonists such as clonidine and guanfacine. Stimulants may temporarily affect appetite, growth, and sleep onset, but comorbid tics are not an absolute contraindication — that old belief has long since been corrected.

In the developing brain, watch which circuit burns too bright; in the aging brain, watch which light goes dark first — get the direction straight, and the symptoms line themselves up.

The core of Tourette syndrome is overactivation of the basal ganglia dopamine system and D2 receptor supersensitivity, so the reasoning chain runs straight through: suppress tics with D2 antagonists, and a dopamine agonist only pours fuel on the fire. Haloperidol, pimozide, risperidone, and aripiprazole can all improve tics; clonidine and guanfacine have fewer side effects and are the common first line, particularly suited to children with comorbid ADHD. Its heritability is high — traditional textbooks describe autosomal dominant inheritance with incomplete penetrance, while the modern view leans toward polygenic inheritance, though the exam still expects the old answer when it poses the question this way. One myth needs debunking: not every patient outgrows it naturally; the tics only partially remit. The core of autism spectrum disorder is deficits in social-emotional reciprocity plus restricted, repetitive behaviors, and the exam loves to ask about treatment, because it slips in the option that sounds most reasonable to deceive you. Applied behavior analysis, early intensive behavioral intervention, and speech therapy are all evidence-based; cognitive behavioral therapy is also effective for comorbid anxiety, depression, and OCD, but sensory integration therapy has no high-quality randomized controlled trial support for the core symptoms of autism — this is the most common trap. Conduct disorder is not a pediatric-only diagnosis; past age 18, if criteria are still met but the threshold for antisocial personality disorder has not been reached, it can still be diagnosed, and the two can even coexist — the diagnosis does not automatically switch on someone's birthday.

The most important thing to remember about normal aging is the direction: dopamine, acetylcholine, norepinephrine, and serotonin all decline together, cerebral blood flow and oxygen utilization decline as well, while IQ is better preserved through crystallized intelligence and can remain stable to about age 80. The exam loves to reverse the direction — seeing "norepinephrine rises with normal aging" should be crossed out immediately. Several geriatric figures are also frequently tested: the prevalence of late-life depression is about 15%, arthritis is the most common cause of disability in the elderly rather than dementia, and persecutory delusions are the most common type of late-onset delusional disorder. New-onset psychotic symptoms in the elderly usually respond to low-dose antipsychotics — "poor response" is a reverse trap — but watch for side effects such as extrapyramidal symptoms and falls.

In the developing brain, watch which circuit burns too bright; in the aging brain, watch which light goes dark first — get the direction straight, and the symptoms line themselves up.

Last comes the differentiation of the dementias. Frontotemporal dementia damages the frontal lobe and anterior temporal lobe, so what collapses first, early on, is personality, behavior, social cognition, and language, while learning and memory are relatively preserved; onset is also earlier, often before age 65. Alzheimer disease damages the medial temporal lobe and hippocampus, so what collapses first, early on, is recent memory, while social cognition is relatively preserved instead. One line to close it out: frontotemporal dementia is the person changed, Alzheimer disease is the facts forgotten. If a question describes FTD's social cognition as preserved early on, that is a reverse trap — it is impaired, not preserved, and getting this direction backward will cost you points across the whole set of linked questions. The entire chapter really comes down to a single habit of mind: first ask whether this brain is heading toward development or decline, then ask which transmitter or which region has gone wrong, and the symptoms will fall into place on their own.

2. The Dopamine Storm: Schizophrenia and Psychosis

🔬 Mechanism, unpacked

Schizophrenia is the classic example of "one disease, two dopamine pathways, opposite directions." Break the causal chain apart: excess DA in the mesolimbic pathway → positive symptoms (hallucinations, delusions); deficient DA in the mesocortical pathway → negative symptoms (flat affect, avolition, withdrawal). Why are there two generations of treatment? First-generation agents strongly antagonize D2 → mesolimbic dopamine is suppressed, positive symptoms improve → but the nigrostriatal pathway is blocked along with it → extrapyramidal symptoms (EPS) and tardive dyskinesia appear; second-generation agents add 5-HT2A antagonism → serotonin's inhibition of striatal DA is lifted → nigrostriatal dopamine is released → EPS decreases → negative symptoms also respond somewhat better. Trap: mistakenly classifying haloperidol as second-generation; assuming "olfactory hallucinations" are most common in schizophrenia (in fact auditory hallucinations are most common, and olfactory hallucinations should instead raise suspicion for temporal lobe epilepsy or an organic cause).

Three Contrasts: Positive vs. Negative, First- vs. Second-Generation, Good vs. Poor Prognosis

Type	Content	Characteristics
Positive symptoms	Hallucinations, delusions, formal thought disorder, bizarre behavior	Prominent in the acute phase; respond better to medication
Negative symptoms	Flat affect, avolition, social withdrawal, impoverished thought, alogia	The long-term core; respond poorly to conventional agents

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

What truly disables patients with schizophrenia over the long term is not hallucinations or delusions but negative symptoms — flat affect, loss of motivation, social withdrawal. They respond poorly to medication and foretell a worse prognosis.

The 4 A's that Bleuler described as primary symptoms form a mnemonic skeleton left over from a century ago: Associations (loosening of associations), Autism (autistic thinking, which emphasizes subjectivity — a self-centered distortion of objective reality), Affect (flattened affect), and Ambivalence. If a question states that "autistic thinking emphasizes objectivity," that reverses the direction and is a trap.

Hallucination, illusion, and delusion are three terms often confused, though their definitions are actually crisp: hallucination = a perception without a stimulus (hearing a voice when no one is speaking); illusion = a stimulus misperceived (mistaking a rope for a snake); delusion = a fixed, false belief (an unshakeable conviction of being monitored, immune to logic). The most common hallucination in schizophrenia is auditory, with command auditory hallucinations being the most classic and the most dangerous; olfactory hallucinations should instead raise suspicion for temporal lobe epilepsy or an organic cause — they are uncommon in schizophrenia, which is exactly the trap the licensing exam loves to dig.

Diagnostic Timeline, Medications, and Clozapine

To diagnose schizophrenia, symptoms (including the active phase) must persist for ≥6 months (including prodromal/residual phases). By contrast: schizophreniform disorder, 1–6 months; brief psychotic disorder, <1 month. The exam loves to swap "6 months" for "1 year" as a trap.

Drug generation	Examples	Mechanism	Features
First-generation (typical)	haloperidol, chlorpromazine	Primarily blocks D2	More EPS; poor for negative symptoms
Second-generation (atypical)	risperidone, olanzapine, aripiprazole, clozapine	Blocks D2 + 5-HT2A	Less EPS; better for negative symptoms

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Remember that haloperidol is first-generation (it is frequently misclassified as second-generation). A key point on side effects: akathisia can be managed with a β-blocker (propranolol); patients who develop EPS early are more likely to later develop tardive dyskinesia.

🔬 Mechanism, unpacked

Clozapine is the special case in this group — it is the only agent with proven efficacy in treatment-resistant schizophrenia, and the only one shown to reduce suicide risk; but because of the risk of agranulocytosis, it requires regular CBC monitoring, so it is never first-line but is instead the reserve trump card for treatment-resistant cases. Other important side effects: lowered seizure threshold, myocarditis (in the first 1–2 months), sialorrhea, decreased bowel motility, and metabolic syndrome. In one sentence: clozapine is the "most effective but most dangerous" drug — to save the sickest patients, you must draw blood the most often. Trap: assuming you should monitor clozapine's serum level (you actually monitor the white cell count); assuming it is first-line (it is reserved for treatment-resistant cases only).

Prognostic Factors: The More "Affective" It Looks, the Better the Outlook

The direction of prognosis also grows straight out of the mechanism: the more a case resembles an affective psychosis (acute onset, a clear precipitating factor, late onset, female, predominantly positive symptoms, a family history of affective illness), the better the prognosis; the more it resembles "pure schizophrenia" (insidious onset, no precipitating factor, early onset, male, prominent negative symptoms, a family history of schizophrenia), the worse the prognosis.

Better prognosis	Worse prognosis
Family history of affective disorder	Family history of schizophrenia
Clear precipitating factor	No precipitating factor
Acute onset	Insidious/gradual
Late onset	Early onset
Female	Male
Predominantly positive symptoms	Prominent negative symptoms

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

A few figures worth memorizing cold: prevalence is about 1%, roughly equal between the sexes — "women are affected twice as often as men" is a common error; age of onset is 15–25 years in men, 20–30 years in women; the lifetime suicide mortality rate was written as about 10% in traditional textbooks (the old 1977 Miles figure), revised by newer meta-analyses to about 5% (4.9%) — but this is still far higher than the general population, and far below inflated options such as "25–50%." Risk factors include depressive episodes, command auditory hallucinations, the period right after discharge, early in the illness course, young men, and the point at which insight has just returned.

Finally, the legal side: involuntary hospitalization must follow the procedures of the Mental Health Act, and a single physician cannot decide it alone — it typically requires a severely ill patient, a risk of harm to self or others, plus a review mechanism. This is a gift question, but "one physician can decide alone" is the trap you must cross out.

⭐ Board-exam essentials

Schizophrenia

Positive symptoms respond well to medication; negative symptoms are the long-term core and the source of disability.
Bleuler's 4 A's: Associations / Autism (subjectivity) / Affect / Ambivalence; "objectivity" is the reverse trap.
Most common hallucination = auditory (command hallucinations are the most dangerous); olfactory hallucinations should raise suspicion for an organic cause/temporal lobe epilepsy.
Diagnostic timeline ≥6 months; schizophreniform 1–6 months; brief psychotic disorder <1 month.
haloperidol = first-generation; treat akathisia with propranolol.
Clozapine is the only agent effective for treatment-resistant disease and the only one that lowers suicide risk; monitor CBC regularly (agranulocytosis).
Prevalence about 1%, roughly equal between sexes; suicide mortality traditionally 10%, newer data about 5%.
Involuntary hospitalization must follow Mental Health Act procedures; not a single physician's call.
Traps: olfactory hallucinations, "objectivity," "6 months" rewritten as "1 year," haloperidol misclassified as second-generation, "women twice as often," a 25–50% suicide rate, involuntary hospitalization by one physician.

♪ Sing-along text — English rendering of the Mandarin song lyrics

A nineteen-year-old male college student is brought into the emergency department by his family. His grades have been sliding for three months, and he has recently started tearing his room apart looking for a listening device, shouting into empty air at midnight, don't tell me to jump. His mother says he has become completely hollow — he will not bathe, will not speak, his eyes have gone vacant. Auditory hallucinations, delusions, plus flat affect and loss of motivation — three clues lined up side by side, pointing to schizophrenia. To understand this disease, start back at the dopamine pathways. Excess dopamine in the mesolimbic system props up the positive symptoms — hallucinations and delusions; deficient dopamine in the mesocortical pathway flattens affect, extinguishes motivation, and drives the social withdrawal that props up the negative symptoms.

Schizophrenia is a dopamine imbalance — too much in the limbic system is noise, too little in the cortex is emptiness; medication suppresses the positive symptoms, but the negative symptoms are the long-term core.

Haloperidol, the representative first-generation antipsychotic, primarily blocks D2 receptors, so it can suppress positive symptoms but is powerless against negative symptoms, and because it blocks dopamine in the nigrostriatal pathway as well, it carries a heavy burden of extrapyramidal side effects. Second-generation drugs block both D2 and 5-HT2A; serotonin's inhibition of striatal dopamine is thereby loosened, so dopamine at the cortical end is somewhat freed up, giving a slightly better effect on negative symptoms and fewer extrapyramidal side effects. The four A's that Bleuler left behind form a mnemonic skeleton from a century ago — loosening of associations, autistic thinking, flattened affect, and ambivalence — and the key to autistic thinking is subjectivity, a self-centered distortion of objective reality; if a question says it emphasizes objectivity, that is a reverse trap. The definitions of hallucination, illusion, and delusion are actually crisp: a hallucination is a perceptual experience arising without any external stimulus, an illusion is a stimulus whose nature is misjudged, and a delusion is a fixed false belief that neither reality nor logic can shake. The most common hallucination in schizophrenia is auditory, with command auditory hallucinations being the most classic and the most dangerous; olfactory hallucinations should instead raise suspicion for temporal lobe epilepsy or another organic cause, because they are actually uncommon in schizophrenia — this is exactly the trap the licensing exam loves to dig.

The diagnostic timeline to remember is six months: symptoms including the active phase must persist for at least six months, counting the prodromal and residual phases as well; one to six months is called schizophreniform disorder, and less than one month is called brief psychotic disorder. The exam loves to misstate six months as one year — cross it out on sight. Haloperidol is first-generation; do not flip this classification. Medication-induced akathisia leaves the patient restless and unable to sit still, pacing back and forth, and is most easily misjudged as agitation, so adding more antipsychotic only makes it worse — the correct management is to reduce the dose or add a β-blocker such as propranolol. Patients who develop extrapyramidal symptoms early are, in the long run, more likely to develop irreversible tardive dyskinesia, which is also why second-generation drugs have an advantage on this point.

Clozapine is the special case in this group: it is the only drug with proven efficacy in treatment-resistant schizophrenia and the only one shown to reduce suicide risk; but the price is the risk of agranulocytosis, so what must be monitored regularly is the white cell count, not the drug level. Because of this risk, it is never first-line but instead the reserve trump card for refractory patients. Other important side effects include a lowered seizure threshold, myocarditis in the first one to two months, decreased bowel motility, sialorrhea, and metabolic syndrome. One line to close it out: clozapine is the most effective but most dangerous drug — to save the sickest patients, you must draw blood the most often.

Prognosis also grows straight out of the mechanism: the more a case resembles affective psychosis, the more optimistic the outlook — acute onset, a precipitating factor, late onset, female, predominantly positive symptoms, and a family history of affective illness are all good prognostic signs; the more it resembles pure schizophrenia, the worse the outlook — insidious onset, no precipitating factor, early onset, male, prominent negative symptoms, and a family history of schizophrenia are all poor prognostic signs. Epidemiology calls for three numbers: prevalence is about one percent and roughly equal between the sexes — "women are affected twice as often as men" is wrong; age of onset runs fifteen to twenty-five years in men, earlier than the twenty to thirty years typical of women; lifetime suicide mortality was written as about ten percent in traditional textbooks, revised by newer meta-analyses to about five percent, but whichever figure is used, it remains far higher than the general population and far below inflated options such as twenty-five to fifty percent. Finally, on the legal side, involuntary hospitalization must follow the procedures of the Mental Health Act, requiring a severely ill patient, a risk of harm to self or others, plus a review mechanism — it is never one physician's call alone.

3. The Rise and Fall of Monoamines and the Amygdala's Alarm: Mood and Anxiety

🩺 At the bedside

Three women take a seat in the clinic, one after another. A 35-year-old new mother has been crying day and night for three weeks, feels "useless," and often lies awake until dawn. A 26-year-old woman falls apart emotionally every week before her period — irritable, throwing things at her family — with symptoms vanishing the moment her period starts. A 22-year-old college student, three weeks after a car accident, still has recurrent nightmares, jumps at the sound of a car horn, and avoids every situation that involves driving. Three stories — major depressive disorder (MDD), premenstrual dysphoric disorder (PMDD), and posttraumatic stress disorder (PTSD), respectively — yet underneath there is only one throughline: the tug-of-war between the monoamines and the amygdala.

The Monoamine Hypothesis of Depression: Learn the Nuclei First, the Direction Second

🔬 Mechanism, unpacked

The most classic model of major depressive disorder is a complete chain: genetics/stress → declining monoaminergic neuron function → insufficient synaptic NE/5-HT/DA → dysregulation of the circuits governing motivation, mood, sleep, and appetite → depressive symptoms; treatment runs the chain backward: antidepressants inhibit reuptake → synaptic monoamines accumulate → downstream receptors adapt → symptoms improve after several weeks. The nuclei of origin for the three transmitters: NE from the locus coeruleus, 5-HT from the raphe nuclei, DA from the VTA and substantia nigra. Trap: describing antidepressants as "enhancing reuptake" (backward — it should be inhibition); swapping the nuclei of origin for NE and 5-HT; remembering only one of the three transmitters.

Neurotransmitter	Nucleus of origin	Relationship to depression
NE (norepinephrine)	Locus coeruleus	Hypofunction
5-HT (serotonin)	Raphe nuclei	Hypofunction
DA (dopamine)	VTA/substantia nigra	Related to motivation and pleasure

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Two more directions — imaging and sleep — are also gift questions. PET: metabolism decreases in the anterior brain (especially the left DLPFC) in depression; mania shows the reverse. Sleep: REM latency shortens in depression (REM sleep begins sooner after falling asleep), with more awakenings, early-morning awakening, and reduced sleep efficiency — "REM latency increases" is the reverse trap.

Bipolar Disorder and the Teratogenicity Mnemonic

The teratogenicity of mood stabilizers in pregnancy is a high-frequency gift question — follow the direction of the organ malformation and it is easy to remember:

Drug	Main teratogenic effect	Pregnancy safety
Lithium	Ebstein anomaly (downward displacement of the tricuspid valve, a cardiac malformation)	Moderate; requires individualized weighing
Valproic acid	Neural tube defects	Should be avoided above all (also affects neurodevelopment)
Carbamazepine	Neural tube defects	High risk
Lamotrigine	Early registries suggested a signal for isolated cleft palate, but the absolute risk is minimal	Relatively the safest

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Mnemonic: lithium → heart (Ebstein), valproate (VPA)/carbamazepine → spine (neural tube). The concept that needs updating: newer large-scale meta-analyses show no significant association between lamotrigine and oral clefts, with an absolute excess risk below 1/550, so valproate is the drug most to be avoided in pregnancy, while lamotrigine is actually one of the relatively safest options. If the exam still gives the old "lamotrigine → oral clefts" as the standard answer, treat it as a historical signal only — do not mistake it for being more dangerous than valproate.

The "Does Not Belong" Trap in PMS/PMDD

Premenstrual syndrome (PMS) occurs during the luteal phase and resolves once menstruation begins; premenstrual dysphoric disorder (PMDD) is the more severe, DSM-5-recognized version, with severe mood instability the week before menstruation. There are two must-know "does not belong" traps here:

Does not belong	Why
Hot flashes do not belong to PMS/PMDD	PMS/PMDD occurs during the luteal phase, when estrogen and progesterone are both still present; hot flashes belong to menopausal estrogen deficiency
Delusions do not belong to PMDD	Delusions are a psychotic symptom requiring a separate diagnosis; they are not a symptom of PMDD

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Suicide Risk: Psychosis Is a High Risk, Not a Protective Factor

High risk	Protective
Psychosis (especially command hallucinations demanding suicide)	Good family relationships
Severe depression, hopelessness	Adequate social support
Social isolation, lack of support	Religious/cultural deterrents
Past suicide attempts, substance abuse	—

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

The exam loves to list psychosis as a "protective factor" — wrong; it is a high-risk factor, especially command hallucinations demanding suicide.

The Anxiety Spectrum: Amygdala Over-Alarm × Timeline

Disorder	Core fear	Key timing/threshold	Hallmark
GAD (generalized anxiety disorder)	Excessive worry about "multiple things"	≥6 months + ≥3 somatic symptoms	Chronic, free-floating anxiety, muscle tension, insomnia
Panic disorder	Sudden, out-of-the-blue panic attacks	Peaks within minutes + ≥1 month of fearing recurrence	Palpitations, sense of impending doom, most likely to rush to the ER
Specific phobia	A single object (heights, needles, animals)	≥6 months	Fear on sight, avoidance
SAD (social anxiety disorder)	Being "judged by others"	≥6 months	Fear of public embarrassment
OCD	Intrusive obsessions	>1 hour per day	Obsessions → compulsions relieve them
ASD (acute stress disorder)	Post-trauma	3 days to 1 month	Dissociation, re-experiencing, hyperarousal
PTSD	Post-trauma	>1 month	4 symptom clusters + negative mood/cognition

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

One line to close it out: ASD and PTSD are two stages of the same illness, and the only difference is "whether a month has passed." Before one month it is called ASD; past one month it is upgraded to PTSD. ASD must include dissociative symptoms (amnesia, derealization, depersonalization) — if a question states "ASD does not include dissociation," that is wrong.

The trap in GAD lies in its course and age of onset. The peak age of onset is relatively young, in the 20s to 30s, with a female-to-male ratio of about 2:1; the course becomes chronic in about 60% of cases, with frequent fluctuation and relapse — it is not a mild illness that resolves easily. The mechanism of panic disorder is a burst of norepinephrine from the locus coeruleus plus a hypersensitive brainstem false-suffocation alarm, which is why patients become convinced they are having a heart attack and have the highest rate of rushing to the emergency department. The circuit in OCD is overactivation of the cortico-striato-thalamo-cortical (CSTC) loop plus serotonergic dysregulation; the formula is that obsessions raise anxiety, compulsions briefly lower it, and the cycle then reinforces itself.

First-Line Medications: SSRI/SNRI + CBT Is the Backbone

First-line medication across nearly the entire anxiety spectrum is SSRI/SNRI, and first-line psychotherapy is CBT. The specific points for each:

OCD: SSRIs often require higher doses and take longer to work; ERP (exposure and response prevention) is the core treatment; treatment-resistant cases can add clomipramine (a potent serotonergic TCA) or augment with a low-dose antipsychotic.
PTSD: first-line treatment is trauma-focused CBT, EMDR; the drugs of choice are SSRI/SNRI (sertraline and paroxetine carry the indication); prazosin (an α1 antagonist) can be added for nightmares/hyperarousal. Benzodiazepines are not recommended in PTSD — they are ineffective and increase the risk of dependence and worsen the long-term course.
Panic disorder: short-term benzodiazepines may be used acutely; long term, SSRI/SNRI + CBT.
GAD: SSRI/SNRI + CBT; buspirone (a 5-HT1A partial agonist) may be used; benzodiazepines only as a short-term bridge.

Last is sex distribution and comorbidity: OCD is roughly equal between the sexes, with earlier onset in men (most other anxiety disorders are more common in women); functional gastrointestinal disorder (IBS) is the most common comorbidity with anxiety disorders, with a comorbidity rate of 40–60%, sharing autonomic hypersensitivity and gut-brain axis dysregulation.

⭐ Board-exam essentials

Mood and Anxiety

Depression monoamines: NE from the locus coeruleus, 5-HT from the raphe nuclei; antidepressants inhibit reuptake.
PET in depression shows decreased anterior (left DLPFC) metabolism; REM latency shortens (not increases).
Bipolar disorder's first episode can be depressive; pregnancy mnemonic: lithium → heart, valproate (VPA)/carbamazepine → spine; valproate is most to be avoided, while lamotrigine is relatively the safest.
PMS/PMDD occur in the luteal phase → do not include hot flashes; PMDD does not include delusions.
Suicide: psychosis is a high-risk factor, not protective.
ASD and PTSD are divided by the one-month mark; ASD must include dissociation.
GAD: ≥6 months, ≥3 somatic symptoms, about 60% become chronic.
First line: SSRI/SNRI + CBT; OCD needs high doses + ERP; PTSD uses prazosin for nightmares, benzodiazepines are not recommended.
OCD is roughly equal between sexes, with earlier onset in men; IBS is the most common anxiety comorbidity.
Traps: antidepressants "enhancing" reuptake, REM latency increasing, bipolar disorder always starting with mania, PMDD including delusions, ASD excluding dissociation, using benzodiazepines in PTSD.

♪ Sing-along text — English rendering of the Mandarin song lyrics

Three women take a seat in the clinic, one after another: a thirty-five-year-old new mother crying day and night, feeling useless, often lying awake until dawn; a twenty-six-year-old woman who falls apart emotionally and throws things every week before her period, with symptoms vanishing the moment her period starts; a twenty-two-year-old college student who, three weeks after a car accident, has recurrent nightmares, jumps at the sound of a car horn, and avoids every situation involving driving. Three stories — depression, premenstrual dysphoria, and posttraumatic stress — yet underneath lies the same single throughline: the tug-of-war between the monoamines and the amygdala.

Low monoamines mean depression, an over-alarmed amygdala means anxiety; antidepressants inhibit reuptake to let the monoamines accumulate, while anxiety has to have its alarm slowly dismantled.

The most classic model of major depressive disorder is monoaminergic hypofunction. Norepinephrine comes from the locus coeruleus, serotonin from the raphe nuclei, and dopamine from the ventral tegmental area and substantia nigra — do not swap these nuclei, since the licensing exam loves to exchange the sources of norepinephrine and serotonin. Declining function produces depression, and the action of antidepressants is to inhibit reuptake so that monoamines accumulate in the synapse — note that it is inhibition, not enhancement, and this direction accounts for the bulk of the reverse traps. All three transmitters are related to depression, and remembering only one of them is also a common mistake. Imaging and sleep are simply extensions of this same chain: in depression, metabolism decreases in the anterior brain, especially the left dorsolateral prefrontal cortex, with mania showing the reverse; sleep shows shortened REM latency, entering REM sooner after falling asleep, not later — this direction is also frequently written backward. The first episode of bipolar disorder can be either a depressive episode or a manic episode, and is not necessarily manic — this is a classic distractor; long-term patients may develop cognitive decline, and those with a family history of schizophrenia also carry a higher risk of developing the disorder, because psychotic disorders cluster within families.

Low monoamines mean depression, an over-alarmed amygdala means anxiety; antidepressants inhibit reuptake to let the monoamines accumulate, while anxiety has to have its alarm slowly dismantled.

The teratogenicity of mood stabilizers in pregnancy is easy to remember by following the direction of the organ affected: lithium harms the heart, causing Ebstein anomaly with downward displacement of the tricuspid valve; valproate and carbamazepine harm the spine, causing neural tube defects; the older literature on lamotrigine once reported a signal for cleft lip and palate, but newer large-scale meta-analyses show an absolute excess risk below one in five hundred fifty, no longer considered significant, so the drug most to be avoided in pregnancy is actually valproate, while lamotrigine is instead one of the relatively safest options. Both premenstrual syndrome and premenstrual dysphoric disorder occur during the luteal phase, when estrogen and progesterone are both still present, so hot flashes are never among the symptoms — hot flashes only occur with the estrogen deficiency of menopause; delusions are a psychotic symptom requiring a separate diagnosis and fall outside the scope of premenstrual dysphoric disorder — these two "does not belong" options are exactly the distractors the exam loves to insert.

Suicide risk assessment has one direction you must never reverse: psychosis is a high-risk factor, not a protective one, especially when command auditory hallucinations demand suicide; the protective factors are family relationships, social support, and religious deterrents. Every disorder on the anxiety spectrum is at its core amygdala hyperarousal combined with insufficient prefrontal inhibition — the only differences are what is feared and for how long. Generalized anxiety disorder requires six months of symptoms plus three somatic symptoms, peaks in onset during the twenties and thirties, and becomes chronic in about sixty percent of cases — it is not a mild anxiety that resolves easily. The mechanism of panic disorder is a burst of norepinephrine from the locus coeruleus plus a hypersensitive brainstem false-suffocation alarm, which is why patients become convinced they are having a heart attack and panic disorder is the anxiety disorder most likely to send someone rushing to the emergency department; the diagnosis requires an attack peaking within minutes plus at least one month of fearing recurrence or a resulting behavior change. The circuit in obsessive-compulsive disorder is overactivation of the cortico-striato-thalamo-cortical loop plus serotonergic dysregulation — obsessions raise anxiety, compulsions lower it, and the cycle then reinforces itself. The two post-trauma stages are the same illness divided by the one-month mark: before one month it is called acute stress disorder, and past one month it is upgraded to posttraumatic stress disorder; the criteria for acute stress disorder explicitly include a cluster of dissociative symptoms — amnesia, derealization, and depersonalization — so if a question states that acute stress disorder does not include dissociation, that is wrong.

Low monoamines mean depression, an over-alarmed amygdala means anxiety; antidepressants inhibit reuptake to let the monoamines accumulate, while anxiety has to have its alarm slowly dismantled.

In terms of medication, first line across the entire spectrum is a serotonin reuptake inhibitor or a serotonin-norepinephrine reuptake inhibitor plus cognitive behavioral therapy — that is the backbone. Each disorder has its own small differences: obsessive-compulsive disorder needs higher doses and takes longer to show benefit, with exposure and response prevention as its core treatment, and treatment-resistant cases can add clomipramine, a potent serotonergic tricyclic antidepressant, or augment with a low-dose antipsychotic. The biggest trap in posttraumatic stress disorder is benzodiazepines — they are not recommended for this disorder, being ineffective while increasing dependence and worsening the long-term course; nightmares and hyperarousal should instead be treated with prazosin, an α1 antagonist; the drugs of choice are serotonin reuptake inhibitors, and the first-line psychotherapies are trauma-focused cognitive behavioral therapy or eye movement desensitization and reprocessing. In panic disorder, short-term benzodiazepines may be used acutely, while the long-term approach is likewise a serotonergic drug plus cognitive behavioral therapy including exposure. Sex distribution and comorbidity are also worth noting: obsessive-compulsive disorder is roughly equal between the sexes with earlier onset in men, the reverse of most other anxiety disorders, which are more common in women; functional gastrointestinal disorders, especially irritable bowel syndrome, are the most common comorbidity with anxiety disorders, with a comorbidity rate of forty to sixty percent, because the two share autonomic hypersensitivity and gut-brain axis dysregulation.

4. Slamming the Brakes and Flooring the Gas: Substances, Emergencies, and Psychiatric Medications

Stimulant vs. Depressant: Intoxication and Withdrawal Run in Opposite Directions

🔬 Mechanism, unpacked

Almost every substance-use question can be cracked with a single principle: intoxication and withdrawal run in opposite directions. The causal chain for depressants: chronic alcohol use → GABA receptors downregulate, NMDA receptors upregulate (the brain compensates by adding its own gas) → once the drug stops, the brake suddenly releases → a surge of excitatory neural activity → seizures, an autonomic storm, delirium tremens (DT) → high mortality. Stimulants run the reverse: chronic use → chronic depletion of synaptic DA/NE, receptor downregulation → once the drug stops → fatigue, hypersomnia, depression, increased appetite → usually not fatal. In one sentence: "the longer the brakes have been pressed, the more dangerous it is to let go." Trap: assuming stimulant withdrawal is the most lethal; assuming haloperidol can be given for alcohol withdrawal (it lowers the seizure threshold and does not protect against DT).

Camp	Representative substances	Intoxication	Withdrawal
Stimulants	Amphetamine, cocaine, caffeine, nicotine	Excitement, agitation, mydriasis, ↑heart rate/blood pressure, paranoia and auditory hallucinations	Fatigue, hypersomnia, depression, ↑appetite
Depressants	Alcohol, benzodiazepines, barbiturates, opioids	Sedation, drowsiness, respiratory depression, miosis (opioids)	Over-excitation, agitation, seizures, autonomic storm

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Alcohol: Memorize "Tremor → Hallucinosis → Seizure → Delirium"

Time (after last drink)	Presentation	Key point
6–8 hours	Tremor, autonomic hyperactivity	Earliest
12–24 hours	Alcoholic hallucinosis	Hallucinations with a clear sensorium
24–48 hours	Withdrawal seizures	Generalized tonic-clonic seizures
48–72 hours	Delirium tremens (DT)	Confusion + hallucinations + autonomic storm; highest mortality

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

The iron rule of treatment: BZDs (lorazepam/diazepam) are first-line for withdrawal, because they show cross-tolerance with alcohol and can prevent seizures and DT; phenobarbital has a narrow safety window and is not first-line. Thiamine (B1) must always be given before glucose — giving glucose first depletes thiamine and can precipitate Wernicke encephalopathy (the triad of ophthalmoplegia, ataxia, and confusion). Hypomagnesemia is a common accompanying finding that should be corrected. Long-term maintenance drugs for sobriety include disulfiram, naltrexone, and acamprosate.

The mechanism of alcoholic blackout is also frequently tested: alcohol inhibits hippocampal NMDA receptors → hippocampal LTP fails → short-term memories cannot consolidate into long-term memory → events occurring "during" intoxication cannot be recalled, long-term memory remains intact, and the person's outward behavior may look normal at the time. So the essence of a blackout is anterograde amnesia within a transient amnesia, not retrograde amnesia, and not a loss of long-term memory.

Stimulants, Opioids, and Others

Amphetamine, methamphetamine, and cocaine are central stimulants; intoxication presents with agitation, paranoia, auditory hallucinations, and cardiovascular events, while withdrawal is the opposite — fatigue, hypersomnia, and depression. Management of amphetamine-induced psychosis: (1) stop the drug (the top priority), (2) for acute psychosis/agitation, use a short-acting antipsychotic such as haloperidol; physical restraint is only for temporary safety purposes. Do not use carbamazepine — it has no established indication for amphetamine-induced psychosis.

Substance	Mechanism/key point	Frequently tested
Ketamine	NMDA receptor antagonist	Dissociative anesthesia, hallucinations, memory impairment; low-dose use studied for treatment-resistant depression
Opioids	μ-receptor agonism	Intoxication: pinpoint pupils + respiratory depression + ↓consciousness; antidote naloxone; withdrawal is miserable but rarely fatal
Caffeine withdrawal	Adenosine receptor rebound	Appears 12–24 hours after stopping; mainly headache + fatigue; no hallucinations or delusions
Nicotine withdrawal	—	Craving, irritability, poor concentration, ↑appetite

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

For chronic insomnia, a short-acting, high-potency hypnotic (such as triazolam) should not be first choice; first-line treatment should be CBT-I, and when medication is used, an agent with an intermediate duration of action is preferred. Combining alcohol with a hypnotic/benzodiazepine produces synergistic central depression, which can cause fatal respiratory depression.

The Logic of Formulation in Psychiatric Drugs: Acute Care Needs "Fast and Titratable"

Scenario	First choice	Rationale
Delirium (non-withdrawal)	Low-dose short-acting oral haloperidol + first find the underlying cause	Titratable, fast onset; a depot injection is wrong
Alcohol/BZD withdrawal delirium	BZD (lorazepam/diazepam)	Cross-tolerance, prevents seizures and DT
Acute agitation, IM route	haloperidol, lorazepam, olanzapine IM	Stable absorption
Unsuitable for IM injection	Diazepam IM	Erratic absorption, poor bioavailability

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Three safety warnings: olanzapine IM must not be combined with a parenteral BZD (there have been reports of fatal cardiorespiratory depression); haloperidol (especially IV) prolongs the QT interval; droperidol carries a black-box warning for QT prolongation.

Which Drugs Require Blood Monitoring, and for What

Drug	Monitoring	Why
Lithium	Serum level (maintenance 0.6–1.0, acute 0.8–1.2 mEq/L) + renal function + TSH	Narrow therapeutic window, high risk of toxicity
Valproic acid	Level (50–100 µg/mL) + liver function + platelets + ammonia	Hepatotoxicity, hyperammonemic encephalopathy
Carbamazepine	Level + CBC + liver function + sodium	Autoinduction of metabolism, bone marrow suppression, SIADH-related hyponatremia
Clozapine	WBC/ANC (serum level not routinely checked)	Agranulocytosis

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Lithium, VPA, and CBZ are monitored by "checking levels" (narrow window); clozapine is monitored by "checking the white cell count" (fear of bone marrow collapse), not by checking its level — do not reverse this.

Clozapine ANC monitoring schedule: weekly at the start → every two weeks after 6 months → monthly after 1 year. ANC <1000/µL warrants stopping the drug. Lithium's long-term side effects are nephrogenic diabetes insipidus (polyuria and thirst) + hypothyroidism + weight gain + tremor + teratogenicity (Ebstein anomaly); precipitants of toxicity = dehydration, NSAIDs, thiazides, ACE inhibitors, a low-sodium diet — all of which cause lithium retention; severe toxicity is cleared by hemodialysis.

Common side effects of SSRIs are nausea, sexual dysfunction, insomnia or hypersomnia, weight change, a bleeding tendency, early agitation, hyponatremia (especially in the elderly, via SIADH), and discontinuation syndrome — "a rapid rise in blood glucose" is not an SSRI side effect; that is a reverse trap. Discontinuation syndrome (from abruptly stopping a short-half-life SSRI such as paroxetine): dizziness, flu-like symptoms, paresthesias (electric-shock sensations), irritability — fluoxetine, with its long half-life, is the least likely to cause it.

The Four Types of EPS: Timing Is the Answer

Type	Timing	Presentation	Management
Acute dystonia	Hours to days	Oculogyric crisis, torticollis, laryngospasm	Anticholinergic (benztropine), diphenhydramine
Akathisia	Days to weeks	Subjective restlessness, pacing	Reduce dose/β-blocker (propranolol); do not mistake it for agitation and increase the dose
Parkinsonism	Weeks to months	Rigidity, resting tremor, bradykinesia	Anticholinergic or dose reduction
Tardive dyskinesia	Months to years	Involuntary orofacial movements, often irreversible	Stop/switch to an atypical agent; VMAT2 inhibitor (valbenazine); anticholinergics make it worse

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

NMS vs. Serotonin Syndrome: Rigidity or Myoclonus?

🔬 Mechanism, unpacked

Back to the two emergency-department beds from the opening: both patients are "febrile, agitated, and racing on autonomic overdrive," but the mechanisms are two opposite chains. Neuroleptic malignant syndrome (NMS): antipsychotics strongly block D2, or L-dopa is abruptly stopped → central DA signaling collapses off a cliff → hypothalamic thermoregulation fails + striatal rigidity → high fever, lead-pipe rigidity, elevated CK, hyporeflexia, slow onset over days; the antidote is to restore DA — dantrolene relaxes the muscles, bromocriptine replenishes dopamine. Serotonin syndrome: an SSRI or MAOI combined with another serotonergic drug (tramadol, linezolid) → synaptic 5-HT accumulates to excess → 5-HT2A is overactivated → autonomic hyperactivity + neuromuscular overexcitation → myoclonus, hyperreflexia, tremor, fast onset over hours; the antidote is cyproheptadine, an antiserotonergic agent. Trap: writing rigidity as serotonin syndrome, or myoclonus as NMS (exactly reversed).

Distinguishing feature	NMS (neuroleptic malignant syndrome)	Serotonin syndrome
Causative drug	Antipsychotics (dopamine blockade), abrupt L-dopa withdrawal	Serotonergic drugs (SSRI, SNRI, MAOI, tramadol, linezolid, etc., in combination)
Onset	Slow (days)	Fast (hours)
Neuromuscular findings	Lead-pipe rigidity, ↓reflexes	Hyperreflexia, myoclonus (especially the lower limbs), tremor
Shared features	Fever, autonomic instability, altered consciousness, ↑CK	Fever, autonomic instability, altered consciousness
Specific antidote	dantrolene, bromocriptine	cyproheptadine

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Rigidity + ↓reflexes + slow onset = NMS; myoclonus + hyperreflexia + fast onset = serotonin syndrome.

Management common to both is to stop the offending drug, cool the patient, provide supportive care, and give fluids; the difference lies in the antidote. The key distinguishing question is "are the muscles rigid or shaking?" — rigid is NMS, shaking is serotonin syndrome.

Other high-yield points on drug safety: the antidote for BZD overdose is flumazenil, but in a chronic user, flumazenil can precipitate withdrawal seizures; TCA overdose causes fatal cardiotoxicity (QRS widening), treated with sodium bicarbonate, which is why patients with depression at suicide risk should not be given large quantities of TCAs; MAOIs combined with tyramine or sympathomimetics cause a hypertensive crisis, and combined with serotonergic drugs cause serotonin syndrome.

⭐ Board-exam essentials

Substances and Psychiatric Medications

Intoxication and withdrawal run in opposite directions; depressant withdrawal can be fatal (alcohol/BZD).
Alcohol withdrawal timeline = tremor (6–8h) → hallucinosis (12–24h) → seizure (24–48h) → DT (48–72h); BZD is first-line, thiamine before glucose.
Blackout = anterograde amnesia, with long-term memory preserved.
Amphetamine-induced psychosis = stop the drug + haloperidol; do not use carbamazepine.
Ketamine = NMDA antagonism; opioid intoxication = pinpoint pupils + respiratory depression, reversed with naloxone.
Delirium: first-line is short-acting oral haloperidol + find the underlying cause; withdrawal delirium: first-line is a BZD.
Diazepam IM has erratic absorption and is unsuitable for acute intramuscular use.
Lithium/VPA/CBZ: check serum levels; clozapine: check the white cell count.
SSRIs do not cause a rapid rise in blood glucose; discontinuation syndrome is least likely with fluoxetine.
EPS: treat akathisia with propranolol, do not increase the dose; tardive dyskinesia = VMAT2 inhibitor, worsened by anticholinergics.
NMS = rigidity + ↓reflexes + slow onset → dantrolene/bromocriptine; serotonin syndrome = myoclonus + hyperreflexia + fast onset → cyproheptadine.
Traps: giving haloperidol for withdrawal delirium, writing SSRIs as causing a blood glucose spike, increasing the dose for akathisia, giving an anticholinergic for TD, and swapping rigidity and myoclonus to the wrong side.

♪ Sing-along text — English rendering of the Mandarin song lyrics

Two beds in the emergency department: in one, a fifty-five-year-old man with alcohol use disorder, three days into abstinence, suddenly trembling, seeing nonexistent insects crawling up the wall, heart rate at one hundred forty, blood pressure one hundred eighty; in the other, a twenty-three-year-old woman taking a serotonin reuptake inhibitor who added the painkiller tramadol on her own, and two hours ago began shaking all over, with myoclonus, a temperature of forty degrees Celsius, and hyperreflexia. Both patients are febrile, agitated, and racing on autonomic overdrive, but in one the brakes have failed and in the other the gas pedal is stuck — and the drugs required are entirely different.

Intoxication and withdrawal run exactly opposite — the brake releases and only the gas is left, so there are seizures; the gas pedal jams, and that is myoclonus. Tell whether it is rigid or shaking, and the antidote follows.

Almost every substance-use question can be cracked with a single principle: the symptoms of intoxication and withdrawal run in opposite directions. With chronic use, a depressant keeps the brakes pressed and the brain enlarges its own gas pedal to compensate; once the drug stops, the brake releases and only a fully open gas pedal is left, so withdrawal brings over-excitation, seizures, and an autonomic storm — this is the fundamental reason alcohol and benzodiazepine withdrawal can be fatal while stimulant withdrawal rarely is. The alcohol withdrawal timeline must be memorized: six to eight hours brings the earliest tremor plus autonomic hyperactivity, twelve to twenty-four hours brings alcoholic hallucinosis with a clear sensorium, twenty-four to forty-eight hours brings generalized withdrawal seizures, and forty-eight to seventy-two hours brings delirium tremens, which carries the highest mortality. The iron rule of treatment is that a benzodiazepine is first-line, because it shows cross-tolerance with alcohol, restores the brake, and prevents seizures and delirium tremens; phenobarbital has a narrow safety window and is not first-line. Vitamin B1 must always be given before glucose — giving glucose first depletes B1 and can precipitate the ophthalmoplegia-ataxia-confusion triad of Wernicke encephalopathy, and magnesium often needs replacing too. The essence of a blackout is inhibition of hippocampal NMDA receptors, so short-term memories cannot consolidate into long-term ones — it is anterograde transient amnesia, not retrograde, with long-term memory preserved and the person's outward behavior possibly looking normal at the time.

On the stimulant side, intoxication with amphetamine, methamphetamine, or cocaine brings agitation, paranoia, auditory hallucinations, and cardiovascular events, while withdrawal is the reverse — fatigue, hypersomnia, depression; management of the acute psychosis is to stop the drug plus give the short-acting antipsychotic haloperidol, and carbamazepine is not used because it has no established indication for amphetamine-induced psychosis. Ketamine is an NMDA receptor antagonist that produces dissociative anesthesia, hallucinations, and memory impairment, and at low doses it has shown rapid onset of benefit in studies of treatment-resistant depression; opioids act through μ-receptor agonism, and the intoxication triad is pinpoint pupils plus respiratory depression plus decreased consciousness, reversed with naloxone, with withdrawal being miserable but rarely fatal. Caffeine withdrawal appears twelve to twenty-four hours after stopping, is dominated by headache plus fatigue, and includes no hallucinations or delusions — describing it as appearing after a week, or as including hallucinations, is always wrong.

The logic of formulation in psychiatric drugs likewise follows the mechanism: acute management needs fast onset, titratability, and monitorability, so the choice is a short-acting drug well absorbed orally or intramuscularly; a long-acting depot injection has a slow onset and cannot be titrated, so it is for maintenance treatment, not acute care. Diazepam is highly lipophilic, so its intramuscular absorption is erratic with poor bioavailability, which is why lorazepam IM, not diazepam IM, is chosen for acute intramuscular injection. Delirium in general has short-acting oral haloperidol as first-line, plus finding the underlying cause, but alcohol and benzodiazepine withdrawal delirium is the exception — a benzodiazepine, not haloperidol, is first-line, because the brake needs restoring to prevent seizures. Three safety warnings: olanzapine IM must not be combined with a parenteral benzodiazepine, since there have been reports of fatal cardiorespiratory depression; haloperidol, especially given intravenously, prolongs the QT interval; and droperidol carries a black-box warning for QT prolongation.

Which drugs need monitoring also should not be reversed: lithium, valproate, and carbamazepine are monitored by checking the serum level, because their therapeutic window is narrow and the risk of toxicity is high; clozapine is monitored by checking the white cell count or absolute neutrophil count, because of the fear of agranulocytosis, not by checking its serum level. The long-term side effects of lithium include nephrogenic diabetes insipidus, hypothyroidism, weight gain, tremor, and teratogenicity in the form of Ebstein anomaly; the precipitants of toxicity are all things that cause lithium retention — dehydration, NSAIDs, thiazide diuretics, ACE inhibitors, a low-sodium diet — and severe toxicity is cleared by hemodialysis. The side effects of serotonin reuptake inhibitors include nausea, sexual dysfunction, insomnia or hypersomnia, weight change, a bleeding tendency, early agitation, hyponatremia in the elderly, and discontinuation syndrome, but a rapid rise in blood glucose is not one of its side effects — that is a reverse trap; discontinuation syndrome is most common with the short-half-life paroxetine and least likely with the long-half-life fluoxetine.

The four types of extrapyramidal symptoms are not arranged at random — onset timing is the axis of management. Acute dystonia appears within hours to days as oculogyric crisis, torticollis, and laryngospasm, treated with the anticholinergic benztropine or diphenhydramine for fast relief; akathisia appears days to weeks later as subjective restlessness and pacing, most easily misjudged as agitation and treated by increasing the dose, which only makes it worse — the correct approach is to reduce the dose or add propranolol; parkinsonism appears weeks to months later as rigidity, resting tremor, and bradykinesia, treated with an anticholinergic or dose reduction; tardive dyskinesia appears months to years later as involuntary orofacial movements that are often irreversible, managed by stopping or switching to an atypical agent and using the VMAT2 inhibitor valbenazine — note that anticholinergics instead worsen it, since those belong to acute dystonia, so do not confuse the two.

Last is the differentiation of those two emergency-department beds. Neuroleptic malignant syndrome is caused by dopamine blockade from antipsychotics: dopamine plunges off a cliff, disabling hypothalamic thermoregulation and producing striatal rigidity, so onset is slow, over days, and the hallmark is lead-pipe rigidity plus decreased reflexes plus elevated CK; the specific antidote is dantrolene to relax the muscles, plus bromocriptine to replenish dopamine. Serotonin syndrome is caused by combining serotonergic drugs — an SSRI, an SNRI, an MAOI, tramadol, linezolid, and the like — so that synaptic 5-HT surges to excess, producing autonomic hyperactivity and neuromuscular overexcitation; onset is therefore fast, over hours, and the hallmark is myoclonus plus hyperreflexia plus tremor, especially in the lower limbs, with cyproheptadine, an antiserotonergic agent, as the specific antidote. Management common to both is to stop the drug, cool the patient, provide supportive care, and give fluids; the difference lies in the antidote. The key distinguishing question is really whether the muscles are rigid or shaking — rigid is neuroleptic malignant syndrome, shaking is serotonin syndrome.

5. The Borderlands of the Mind: Somatic Symptoms, Dissociation, Personality, and Ethics

🩺 At the bedside

Four patients lie side by side on the ward. A 30-year-old woman has "glove-and-stocking" numbness and reduced muscle strength, and every finding on neurological exam fails to match any actual nerve distribution. A 22-year-old woman has a body mass index of 14, a heart rate of 38, a temperature of 35°C, and no period for six months. A 28-year-old woman repeatedly self-harms, one moment idolizing the head nurse and the next calling her garbage, chronically empty inside. In the next bed, a terminally ill patient, fully lucid, insists on refusing dialysis, while the family wants him forced to continue. Four stories — conversion disorder, anorexia nervosa, borderline personality disorder (BPD), and end-of-life ethics, respectively — and this chapter is devoted entirely to these "borderlands of the mind."

The Somatic Symptom Group: Two Axes, One Clean Cut

Two axes cut cleanly through this group of disorders:

Is the symptom deliberately produced?	Is there a tangible external benefit?	Diagnosis
No (produced unconsciously)	—	Conversion disorder / SSD
Yes (deliberate)	No (solely to occupy the "sick" role)	Factitious disorder
Yes (deliberate)	Yes (evading duty, insurance fraud, seeking drugs)	Malingering = not a mental disorder

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Factitious disorder is about the role of being a patient for its own sake; malingering is about the benefits that come with the patient role. Deliberately feigning illness with no external benefit is factitious disorder, not malingering.

Conversion Disorder: A Neurological Exam That "Doesn't Fit" Is the Answer

The core of conversion disorder (also called functional neurological symptom disorder, FND, in DSM-5) is that psychological stress is "converted" into a neurological symptom, yet examination findings are internally inconsistent with neuroanatomy — a "glove-and-stocking" sensory deficit that matches no actual nerve distribution is the classic example. The most common symptom is limb weakness/paralysis, followed by gait abnormalities and psychogenic non-epileptic seizures (PNES); PNES can coexist with true epilepsy, so the presence of these episodes cannot be used to rule out true epilepsy.

Two clues that support the diagnosis are often flipped into mistaken grounds for "ruling it out": improvement in response to suggestion, hypnosis, or lorazepam supports the diagnosis of conversion disorder — it cannot be used to "rule it out just because a drug worked"; la belle indifférence (indifference toward a serious symptom) can be seen in conversion disorder but is neither specific nor required.

Questions on therapeutic attitude are a favorite: build trust, acknowledge that the symptom is genuinely real, provide psychotherapy (CBT) + rehabilitation, and address the underlying stressor. The cardinal sin is telling the patient outright, "this is all in your imagination" — it destroys the therapeutic relationship and accomplishes nothing, because to the patient, the symptom of conversion disorder is real and not deliberately produced.

BDD, Dissociation, and Confabulation

Body dysmorphic disorder (BDD) involves a distorted, fixed, negative belief about some flaw in one's appearance that others barely notice, and it belongs to the obsessive-compulsive-related disorder spectrum. First-line treatment is SSRI + CBT; cosmetic surgery/procedures are ineffective and can even be harmful — fixing one perceived flaw simply shifts the attention to the next one, and the demands only multiply, never diminish.

The core of dissociative disorders is that the continuity of consciousness, memory, identity, or perception is "disconnected," most often related to trauma. DSM-5 has downgraded dissociative fugue to a "with fugue" specifier under dissociative amnesia; dissociative identity disorder (DID) consists of ≥2 distinct personality states alternating with amnesia; a person with depersonalization/derealization feels that they themselves, or the world, is unreal, but reality testing remains intact (they know it is only a "feeling" of unreality).

Confabulation is not dissociation — it is a memory disorder: without any intent to deceive, the patient fills gaps in memory with fabricated content, classically seen in Korsakoff syndrome (thiamine/B1 deficiency, commonly from chronic alcohol use); it belongs to the domain of memory, not language, emotion, thought, or dissociation.

Psychiatric complications after organ transplantation: the high-risk conditions are adjustment disorder, major depression, PTSD (especially ICU-related), and delirium; delusional disorder is the least likely — when the exam asks "which is least likely to appear after transplantation," choose delusional disorder.

Eating Disorders: The Key Dividing Line Between AN and BN

Item	AN (anorexia nervosa)	BN (bulimia nervosa)
Weight	Significantly low	Usually normal or overweight
Core feature	Restricted energy intake, intense fear of gaining weight, distorted body image	Recurrent binge eating + compensatory behavior (vomiting/laxatives/excessive exercise)
Self-evaluation	Unduly influenced by body shape/weight	Unduly influenced by body shape/weight (explicit in DSM-5)
Frequency/duration	—	≥1 time/week, ≥3 months
Mortality	Among the highest in psychiatry	Lower
Drug of choice	No specific drug (nutrition/psychotherapy are the mainstay); bupropion contraindicated	Fluoxetine 60 mg/day (the only FDA-approved agent); bupropion contraindicated

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Every physiologic complication of AN is a compensation for "chronic malnutrition + low body fat": hypothermia (↓body fat, ↓metabolic rate), bradycardia and hypotension (↑vagal tone), amenorrhea (↓hypothalamic GnRH → hypogonadotropic hypoestrogenism), osteoporosis (low estrogen + malnutrition), lanugo (a compensatory attempt to conserve heat), and vomiting/laxatives → hypokalemia plus metabolic alkalosis (loss of gastric acid and potassium). One direction worth spelling out explicitly: what vomiting causes is hypokalemia, not hyperkalemia.

Indications for hospitalization: weight roughly <70–75% of ideal body weight, severe arrhythmia/electrolyte abnormalities (hypokalemia/hypophosphatemia), unstable vital signs (heart rate <40, hypotension/hypothermia), acute food refusal, or suicide risk. The admitting department is chosen according to the complications — psychiatry or internal medicine/pediatrics — not automatically pediatrics. Refeeding syndrome results from rapid refeeding → insulin surges → hypophosphatemia, hypokalemia, hypomagnesemia → arrhythmia/heart failure, so calories should be increased slowly, with phosphate repletion.

Weight regain after bariatric surgery is multifactorial — reverting behavior/eating habits, psychological factors, changes in the microbiome, anatomical compensation; replacing B12/iron only addresses the nutritional deficiencies of postoperative malabsorption and has nothing to do with preventing weight regain — this is a reverse trap.

Personality Disorders: A Is Weird, B Is Wild, C Is Worried

Cluster	Mnemonic	Representative disorders
Cluster A: odd/eccentric	Weird	Paranoid, schizoid, schizotypal
Cluster B: dramatic/emotional	Wild	Antisocial, borderline (BPD), histrionic, narcissistic
Cluster C: anxious	Worried	Avoidant, dependent, obsessive-compulsive (OCPD)

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

The picture of borderline personality disorder (BPD) is extreme emotional instability, chronic emptiness, an intense fear of abandonment, recurrent self-harm/suicidal threats, brief dissociation/quasi-psychotic symptoms under stress, and interpersonal relationships that swing between idealization and devaluation. First-line treatment is dialectical behavior therapy (DBT) — the psychotherapy with the strongest evidence base; psychotherapy plus medication has a synergistic effect; benzodiazepines are ineffective for BPD's core symptoms and carry a risk of dependence/disinhibition. The exam loves to mistake BPD for "dependent personality disorder," or to make a benzodiazepine the mainstay of treatment — both should be crossed out.

Defense Mechanisms and Impulse Control

Mechanism	Definition	Example
Fantasy	Drawing comfort from imagined relationships	An imaginary friend
Dissociation	Loss of identity coherence after intense stress	Suddenly not knowing who one is
Isolation of affect	Describing an emotional event in detail while severing the emotion	Recounting the details of a car crash in a flat tone
Projection	Attributing one's own unacceptable motives to others	Accusing the doctor of incompetence to escape one's own responsibility
Reaction formation	Masking an impulse with the opposite behavior	Being excessively attentive to someone one despises
Sublimation (mature)	Redirecting an impulse into a socially acceptable channel	Aggression → boxing

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

Kleptomania is at its core an impulsive impulse-control disorder: rising tension before the theft, a sense of relief after the act, and the stolen items are usually not needed and the person could afford to buy them. The difference from ordinary theft lies in "planning and motive" — ordinary theft is planned and for the value of the object; kleptomania is unplanned and not for the object's value. If a question states that "kleptomania is planned and carefully premeditated," that is a reverse trap.

Gender dysphoria in children: diagnostic criterion A1 requires a strong desire to be of another gender; both children and adolescents/adults require symptoms to persist for ≥6 months (not adults only); a disorder of sex development (DSD) does not need to be excluded — it can be noted as a specifier; the APA explicitly opposes conversion/reparative therapy, favoring affirmative care instead.

Ethics: Weighing the Four Principles

Principle	Core idea	Application
Autonomy	Respecting the patient's own decision	Informed consent, refusal of treatment, confidentiality
Beneficence	Acting in the patient's best interest	Providing beneficial treatment
Non-maleficence	Do no harm	Avoiding futile/harmful interventions
Justice	Fair distribution	Organ allocation, health insurance

Swipe or scroll sideways to compare every column; keyboard: focus the table and use arrow keys.

The three requirements for a valid autonomous decision are: decision-making capacity + adequate disclosure + voluntariness. So the terminally ill patient in the next bed, with normal consciousness and cognition, who repeatedly and consistently refuses dialysis — the principle of autonomy dictates that his decision should be respected, with no need for a court or legal representative to intervene. Situations in which informed consent may be waived or modified include: an emergency (presumed consent), lack of decision-making capacity (a surrogate decides), the patient voluntarily waiving disclosure (documented), and therapeutic privilege (a high bar, not to be abused).

The duty of confidentiality is not absolute — it may be broken when there is serious, imminent harm to an identifiable third party (drawing on the spirit of Tarasoff). A classic exam question: a patient with HIV refuses to inform a sexual partner, and the partner is already pregnant → the physician may disclose to protect the third party. First urging the patient to disclose voluntarily is the reasonable first step; if the patient still refuses, the physician may then disclose — that is the most appropriate approach. "Only reminding the patient to disclose" falls short, while "fully releasing the patient's personal information" violates the principle of proportionality.

The classification of euthanasia turns on whether the physician "actively did something that caused death" or "stopped providing life support": active euthanasia (actively administering a lethal means) is illegal in most jurisdictions; passive euthanasia (withdrawing/withholding life support) is more widely accepted; physician-assisted suicide (PAS) sits between the two; the doctrine of double effect (giving a sufficient dose of morphine to relieve suffering, where hastening death is foreseen but not intended) is ethically acceptable. Withdrawing and withholding treatment are ethically and legally equivalent — removing a ventilator from a patient with capacity, at that patient's own wish, is lawful and falls under patient autonomy; it is not equivalent to killing. Misclassifying "actively assisting death" as passive euthanasia is the most inappropriate description.

Genetic testing mostly provides only a probability of disease risk, not an accurate prediction; organ donation must respect the donor's wishes plus honest disclosure — the family must never be deceived; having a 12-year-old minor sister donate a kidney raises child-protection ethics concerns and is not permitted.

⭐ Board-exam essentials

Somatic Symptoms, Dissociation, Personality, Eating Disorders, and Ethics

SSD no longer requires "medically unexplained"; the DSM-5 focus is on an excessive response.
Two axes: deliberate × external benefit — not deliberate = conversion disorder; deliberate + no benefit = factitious disorder; deliberate + benefit = malingering (not a mental disorder).
Most common in conversion disorder = limb weakness/paralysis; response to suggestion/lorazepam = supports the diagnosis; la belle indifférence is not specific; never say "it's imagined."
BDD = SSRI + CBT; cosmetic surgery is ineffective and harmful.
DID = ≥2 personality states + amnesia; depersonalization has reality testing that stays intact; confabulation = a memory disorder (Korsakoff/B1 deficiency), not dissociation.
After transplantation, the least likely diagnosis = delusional disorder.
AN = significantly low body weight; DSM-5 has removed amenorrhea as a criterion; a person at low body weight is still AN (binge-eating/purging type) even with binge eating/purging.
AN complications: hypothermia, bradycardia, amenorrhea, osteoporosis, lanugo; vomiting → hypokalemia (not hyperkalemia); hospitalize below 70% of ideal body weight (current SAHM 2022: below 75% of median BMI); refeeding syndrome = hypophosphatemia/hypokalemia/hypomagnesemia; weight regain after bariatric surgery is multifactorial, and B12/iron cannot prevent it.
BN: binge eating + compensation + self-evaluation influenced by weight; first-line fluoxetine 60 mg; bupropion is contraindicated in both AN and BN (seizure risk).
BPD first-line is DBT; benzodiazepines are ineffective and carry a risk of dependence.
Kleptomania = impulsive, unplanned, not for the object's value; gender dysphoria criterion A1 = desire to be the other gender, children too require ≥6 months, conversion therapy is opposed.
Ethics: autonomy wins out for a patient with capacity; confidentiality is not absolute (may be broken to protect a third party); active vs. passive euthanasia is divided by "administering death" vs. "withdrawing support"; withdrawing and withholding are equivalent; genetic testing is risk assessment, not prediction; organ donation must never deceive the family.
Traps: writing SSD as "requiring no cause found," calling conversion disorder "imagined," requiring amenorrhea for AN, hyperkalemia from vomiting, using benzodiazepines for BPD, forcing a terminal patient onto dialysis, deceiving a family to encourage donation.

♪ Sing-along text — English rendering of the Mandarin song lyrics

Four patients lie side by side on the ward: a thirty-year-old woman with glove-and-stocking numbness and reduced muscle strength that fails to match any nerve distribution on every test; a twenty-two-year-old woman with a body mass index of fourteen, a heart rate of thirty-eight, a temperature of thirty-five degrees, and no period for six months; a twenty-eight-year-old woman who repeatedly self-harms, one moment treating the head nurse as a god and the next as garbage, chronically empty inside; and in the next bed, a terminally ill patient, fully lucid, insisting on refusing dialysis, while the family wants him forced to continue. Conversion disorder, anorexia nervosa, borderline personality disorder, and end-of-life ethics — this chapter is devoted entirely to these borderlands of the mind.

Don't rush to name the diagnosis — cut it first along two axes: deliberate or unconscious, an external benefit or none, and whose brain, which circuit, has been disconnected.

What the somatic symptom group shares is somatic discomfort plus excessive thoughts, feelings, or behaviors about the symptoms. There is one major DSM-5 change to remember: somatic symptom disorder no longer requires that symptoms be medically unexplained — even when the patient genuinely has coronary artery disease, the diagnosis can still be made as long as the response to the symptoms is excessive and disproportionate; defining it as no cause found on workup is outdated older thinking. To cut cleanly through this group, use two axes: whether the symptom is deliberately produced, and whether there is a tangible external benefit. Not deliberate is conversion disorder or somatic symptom disorder, where the patient's suffering is genuine; deliberate but only to occupy the patient role is factitious disorder; deliberate with an external benefit, such as evading duty or insurance fraud, is malingering, which is not a mental disorder. The core of conversion disorder is that psychological stress is converted into a neurological functional symptom, yet the findings are internally inconsistent with neuroanatomy — glove-and-stocking numbness is the classic example; the most common symptom is limb weakness or paralysis, followed by gait abnormality and psychogenic non-epileptic seizures, which can coexist with true epilepsy, so the episodes cannot be used to rule out true epilepsy. Responding to suggestion, hypnosis, or lorazepam supports the diagnosis rather than being grounds for ruling it out, and this direction accounts for the bulk of the reverse traps; indifference toward a serious symptom can be seen in conversion disorder but is neither specific nor required. The therapeutic attitude is to build trust, acknowledge that the symptom is genuinely real, provide cognitive behavioral therapy plus rehabilitation, and address the underlying stressor; the cardinal sin is telling the patient outright that this is something they have imagined, which destroys the relationship and accomplishes nothing, because to the patient the symptom is real and not deliberately produced.

Body dysmorphic disorder belongs to the obsessive-compulsive-related disorder spectrum, with first-line treatment being a serotonin reuptake inhibitor plus cognitive behavioral therapy; cosmetic surgery and procedures are ineffective and can even be harmful — fixing one flaw simply shifts the attention to the next, and the demands only grow, never shrink. Dissociative disorders involve a disconnection in the continuity of consciousness, memory, identity, or perception, most often related to trauma; DSM-5 has downgraded dissociative fugue to a "with fugue" specifier under dissociative amnesia, dissociative identity disorder consists of two or more personalities alternating with amnesia, and a person with depersonalization feels that they themselves or the world is unreal, yet reality testing remains intact. Confabulation is not dissociation but a manifestation of a memory disorder — the patient fills gaps with fabricated content without any intent to deceive, classically seen in Korsakoff syndrome, that is, B1 deficiency most often seen in chronic alcohol use; do not confuse this classification. The psychiatric complication least likely after organ transplantation is delusional disorder, while the high-risk conditions are adjustment disorder, major depression, posttraumatic stress disorder — especially ICU-related — and delirium.

Don't rush to name the diagnosis — cut it first along two axes: deliberate or unconscious, an external benefit or none, and whose brain, which circuit, has been disconnected.

The core of every eating disorder is that self-evaluation is held hostage by body shape and weight. Anorexia is defined by significantly low body weight, bulimia by compensatory behavior combined with self-evaluation unduly influenced by weight; there are two important DSM-5 changes to remember — anorexia has removed amenorrhea as a required diagnostic criterion, and it no longer mandates a fixed BMI cutoff, replacing it with significantly low body weight relative to what the person needs; a person who has reached significantly low body weight is still diagnosed with the binge-eating/purging type of anorexia even with binge eating or purging present, not with bulimia. The physiologic complications of anorexia are all compensations for chronic malnutrition plus low body fat: low body fat and a falling metabolic rate cause hypothermia, rising vagal tone causes bradycardia and hypotension, falling hypothalamic GnRH causes the hypogonadotropic hypoestrogenism behind amenorrhea, low estrogen plus malnutrition causes osteoporosis, the skin grows lanugo to conserve heat, and vomiting or laxatives cause hypokalemia and metabolic alkalosis — it is hypokalemia, not hyperkalemia. Indications for hospitalization are a weight roughly below seventy percent of ideal body weight, severe arrhythmia or electrolyte abnormality, unstable vital signs, or acute food refusal with suicide risk, with admission chosen according to the complications — psychiatry or internal medicine/pediatrics — rather than automatically pediatrics. Refeeding syndrome follows rapid refeeding, when a surge of insulin drives phosphate, potassium, and magnesium into cells and causes arrhythmia and heart failure, so calories must be increased slowly with phosphate repletion. Weight regain after bariatric surgery is multifactorial, and replacing B12 and iron only addresses the nutritional deficiencies of postoperative malabsorption — it cannot prevent weight regain. First-line treatment for bulimia is fluoxetine at sixty milligrams a day, higher than the antidepressant dose; bupropion is contraindicated in both anorexia and bulimia because of seizure risk.

Personality disorders divide into three clusters: Cluster A, odd/eccentric — Weird — includes paranoid, schizoid, and schizotypal; Cluster B, dramatic/emotional — Wild — includes antisocial, borderline, histrionic, and narcissistic; Cluster C, anxious — Worried — includes avoidant, dependent, and obsessive-compulsive personality disorder. The picture of borderline personality disorder is extreme emotional instability, chronic emptiness, an intense fear of abandonment, recurrent self-harm and suicidal threats, brief dissociation or quasi-psychotic symptoms under stress, and interpersonal relationships swinging between idealization and devaluation. First-line treatment is dialectical behavior therapy, the psychotherapy with the strongest evidence base; psychotherapy plus medication has a synergistic effect; benzodiazepines are ineffective for the core symptoms and carry a risk of dependence and disinhibition, so they cannot be the mainstay. The exam loves to mistake borderline for dependent personality disorder, or to make a benzodiazepine the first choice — both should be crossed out. Questions defining the defense mechanisms love to dig pits: fantasy is drawing comfort from imagined relationships, dissociation is a loss of identity coherence after intense stress, isolation of affect is describing an event in detail while severing the emotion, recounted in a flat tone, projection is attributing one's own unacceptable motives to others to escape responsibility, reaction formation is masking an impulse with the opposite behavior, and sublimation, redirecting an impulse into a socially acceptable channel, is the representative mature mechanism. Kleptomania is at its core impulsive: tension rises before the theft, relief follows the act, and the stolen items are usually not needed and the person could afford to buy them; the difference from ordinary theft lies in planning and motive — ordinary theft is planned and for the value of the object — so saying kleptomania is carefully premeditated is a reverse trap. The A1 criterion for gender dysphoria in children is a strong desire to be of another gender; children, adolescents, and adults alike require symptoms to persist for at least six months, not adults only; a disorder of sex development does not need to be excluded and can be noted as a specifier; the APA explicitly opposes conversion or reparative therapy and calls for affirmative care instead.

Last is ethics. The four principles are autonomy, beneficence, non-maleficence, and justice; most ethics questions are at their core a conflict between two of these principles — locate the conflict first, then weigh it. For a patient with decision-making capacity, the principle of autonomy usually wins out, unless a third party is endangered. The three requirements for a valid autonomous decision are capacity plus adequate disclosure plus voluntariness; the terminally ill patient with normal consciousness and cognition who repeatedly and consistently refuses dialysis should, under the principle of autonomy, have his decision respected, with no need for a court or legal representative to intervene — this is a gift question, yet also one of the most commonly missed. Situations in which informed consent may be waived or modified are: presumed consent in an emergency, a surrogate deciding by the patient's best interest when capacity is absent, the patient voluntarily waiving disclosure with documentation, and the rare case of therapeutic privilege, whose bar is very high and must not be abused. The duty of confidentiality is not absolute and may be broken when there is serious, imminent harm to an identifiable third party, drawing on the spirit of the Tarasoff duty to protect; in the scenario of a patient with HIV who refuses to inform a sexual partner and the partner is already pregnant, first urging the patient to disclose voluntarily is the reasonable first step, and if the patient still refuses, the physician may then disclose — that is the most appropriate approach; merely reminding the patient to disclose falls short, and fully releasing the patient's personal information violates the principle of proportionality. The classification of euthanasia turns on whether the physician actively did something that caused death or simply stopped providing life support: active euthanasia, actively administering a lethal means, is illegal in most jurisdictions; passive euthanasia, withdrawing or withholding life support, is more widely accepted; physician-assisted suicide sits between the two; the doctrine of double effect, giving a sufficient dose of morphine to relieve suffering where hastening death is foreseen but not intended, is ethically acceptable; withdrawing and withholding are ethically and legally equivalent, and misclassifying actively assisting death as passive euthanasia is the most inappropriate description. Genetic testing is mostly a risk assessment rather than an accurate prediction; organ donation must respect the donor's wishes plus honest disclosure, the family must never be deceived, and having a twelve-year-old minor sister donate a kidney raises child-protection ethics concerns and is not permitted.

Don't rush to name the diagnosis — cut it first along two axes: deliberate or unconscious, an external benefit or none, and whose brain, which circuit, has been disconnected.