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Psychiatry · Psychiatry

Schizophrenia & Psychotic Disorders

A boards-focused tour of schizophrenia and the psychotic-disorder spectrum: DSM-5 criteria and the duration cutoffs that separate them, classic vignette buzzwords, first-line atypical antipsychotics through clozapine for refractory disease, and next-best-step handling of EPS and NMS.

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The Psychotic Spectrum: What Boards Test

Psychosis = loss of contact with reality: delusions, hallucinations, disorganized speech, and disorganized or catatonic behavior. Schizophrenia is the prototype, and the whole family of psychotic disorders is separated mainly by how long symptoms last.

Symptoms cluster into three domains:

  • Positive (added experiences): hallucinations — classically auditory — delusions, disorganized speech/behavior. Reflect mesolimbic dopamine excess; respond best to antipsychotics.
  • Negative (lost function): flat affect, alogia, avolition, anhedonia, asociality. Linked to mesocortical dopamine deficit; hardest to treat and the main driver of long-term disability.
  • Cognitive: impaired attention and working memory.

Dopamine hypothesis = excess D2 signaling in the mesolimbic tract. Glutamate/NMDA hypofunction also matters — this is why PCP and ketamine reproduce psychosis.

Epidemiology: lifetime prevalence ~1% (0.3–0.7%), roughly equal in men and women. Onset is typically early 20s in men, late 20s in women (women have a later, second peak after 40). Earlier onset and male sex predict worse prognosis. Strong heritability (monozygotic twin concordance ~50%). Lifetime completed-suicide risk ~5% (attempts far more common).

DSM-5 Criteria + Duration Cutoffs

DSM-5 schizophrenia — the tested framework:

  • Criterion A: ≥2 of 5 symptoms for a significant portion of ≥1 month, and at least one must be delusions, hallucinations, or disorganized speech (the other two: grossly disorganized/catatonic behavior; negative symptoms).
  • Criterion C (duration): continuous signs for ≥6 months, including ≥1 month of active-phase (Criterion A) symptoms; may include prodromal/residual periods.
  • Plus: significant functional decline; must rule out schizoaffective/mood disorder, substances, and medical causes.

Duration is the whole game for the shorter psychoses:

  • Brief psychotic disorder: ≥1 day but <1 month, with full return to baseline (often after a stressor or postpartum).
  • Schizophreniform: 1 to 6 months.
  • Schizophrenia: ≥6 months.

Buzzword pearls:

  • Auditory hallucinations are most common; visual/olfactory/tactile hallucinations should prompt a hunt for an organic cause.
  • Waxy flexibility / posturing = catatonia.
  • Downward socioeconomic drift is associated with the illness.
Diagram of the four major dopaminergic pathways in the human brain: mesolimbic, mesocortical, nigrostriatal, and tuberoinfundibular.
Dopamine pathways: mesolimbic excess drives positive symptoms and mesocortical deficit drives negative symptoms, while D2 blockade in the nigrostriatal and tuberoinfundibular tracts explains EPS and hyperprolactinemia. · Wikimedia Commons — User:Slashme; Patrick J. Lynch; User:Fvasconcellos — CC BY-SA 4.0, via Wikimedia Commons

Psychotic Disorders — Timeframes & Criteria

DisorderDurationHallmark
Brief psychotic disorder≥1 day, <1 month, returns to baselineOften stress-triggered or postpartum
Schizophreniform1 to <6 monthsSame Criterion A as schizophrenia; functional decline not required
Schizophrenia≥6 months (≥1 mo active)Functional decline required
Schizoaffective≥2 weeks of psychosis without a major mood episodeMood episodes present for the majority of the illness
Delusional disorder≥1 monthClassically non-bizarre delusion; functioning otherwise intact; no other prominent Criterion A symptoms
Schizotypal PDLifelong patternOdd/magical thinking, eccentric — no frank/sustained psychosis
Vignette: First-Episode Psychosis

Vignette: A 21-year-old college student is brought in after 7 months of decline. He hears voices commenting on his actions, believes classmates are spying on him, gives rambling disorganized answers, has withdrawn from friends, and is failing his courses. He denies drug use; vitals are normal.

Diagnosis: Schizophrenia — ≥2 Criterion A symptoms (hallucinations, delusions, disorganized speech), >6 months, with clear functional decline.

Next best step: Before committing to the label, exclude substance-induced and medical causes — order a urine toxicology screen (plus CBC, metabolic panel, TSH; consider first-episode/infectious workup). Substance-induced psychosis and delirium are the mimics a first-episode question wants you to rule out.

Then: start a second-generation (atypical) antipsychotic and connect to psychosocial support. Key trap: a single delusion/hallucination or symptoms lasting <1 month is not schizophrenia — mind the duration thresholds.

Management: First-Line Meds → Clozapine → Therapy

Management of schizophrenia:

  • First-line = second-generation (atypical) antipsychotics (risperidone, olanzapine, quetiapine, aripiprazole). First-generation agents are equally effective for positive symptoms but cause more EPS.
  • Choose by side-effect profile; monitor weight, fasting glucose, and lipids (metabolic syndrome — worst with olanzapine and clozapine).
  • Nonadherence → switch to a long-acting injectable.
  • Treatment-resistant (failed ≥2 adequate antipsychotic trials) → clozapine, the most effective agent and the one proven to reduce suicidality. Requires ANC monitoring for agranulocytosis; also watch for myocarditis, seizures, and sialorrhea.
  • Psychosocial therapy is adjunctive, never monotherapy: CBT for psychosis, family psychoeducation, assertive community treatment, supported employment, social-skills training.
  • Treat early — a longer duration of untreated psychosis predicts worse outcomes.

Antipsychotic Side Effects — Know Cold

Agent / classKey adverse effectsBoard pearl
High-potency FGA (haloperidol, fluphenazine)EPS, hyperprolactinemia, NMSHighest EPS risk
Low-potency FGA (chlorpromazine, thioridazine)Anticholinergic, sedation, orthostasisChlorpromazine → corneal deposits; thioridazine → retinal deposits + QT
Atypicals (class)Metabolic syndrome, weight gainOlanzapine & clozapine worst
ClozapineAgranulocytosis, seizures, myocarditis, sialorrheaRefractory disease only; monitor ANC
RisperidoneHyperprolactinemia (galactorrhea, gynecomastia)Most prolactin among atypicals
ZiprasidoneQT prolongationCheck baseline ECG
AripiprazoleAkathisiaPartial D2 agonist; relatively weight-neutral
5 A's + the EPS 'Rule of 4s'

Negative symptoms — the 5 A's:

  • Affective flattening (blunted/flat affect)
  • Alogia (poverty of speech)
  • Avolition (lack of motivation/initiative)
  • Anhedonia
  • Asociality

Extrapyramidal side effects — the 'rule of 4s' (approximate onset after starting an antipsychotic):

  • 4 hours–4 days → acute Dystonia (oculogyric crisis, torticollis) → benztropine or diphenhydramine
  • 4 days → Akathisia (inner restlessness, can't sit still) → propranolol, lower the dose
  • 4 weeks → Parkinsonism (bradykinesia, tremor, rigidity) → benztropine or amantadine
  • 4 months → Tardive dyskinesia (orobuccolingual chorea) → VMAT2 inhibitors (valbenazine, deutetrabenazine); avoid anticholinergics (they worsen it)
Vignette: The Antipsychotic Emergency (NMS)

Vignette: Three days after haloperidol was started, a patient develops temperature 40°C, 'lead-pipe' rigidity, fluctuating consciousness, and autonomic instability (labile BP, tachycardia, diaphoresis). Labs: markedly elevated CK and leukocytosis.

Diagnosis: Neuroleptic malignant syndrome (NMS) — an idiosyncratic reaction to dopamine blockade; highest risk with high-potency typicals and after dose increases.

Next best step: Stop the antipsychotic immediately and give aggressive supportive care (IV fluids, active cooling, watch for rhabdomyolysis/AKI). For severe cases add dantrolene and/or a dopamine agonist (bromocriptine, amantadine).

Contrast — serotonin syndrome: serotonergic drug, rapid onset (<24 h), hyperreflexia/clonus (vs rigidity + normal-to-decreased reflexes in NMS) → treat with cyproheptadine.

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