Step 2 CK · Psychiatry

Psychotic Disorders

Name: Psychotic Disorders
Creator: Veli Bakalov, MD

Timing the psychoses, driving dopamine down, and dodging the drug reactions

Psychiatry·Psychotic Disorders & Catatonia·5 min read·9 high-yield points·Reviewed by Veli Bakalov, MD @HemeOncBuddy

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Schizophrenia = ≥2 of 5 core symptoms (at least one of delusions, hallucinations, or disorganized speech) with ≥1 month active phase, ≥6 months total disturbance, and functional decline.
Duration ladder: brief psychotic disorder 1 day to <1 month (full recovery), schizophreniform 1–6 months, schizophrenia ≥6 months.
Schizoaffective disorder requires ≥2 weeks of psychosis without mood symptoms; psychosis only during mood episodes = mood disorder with psychotic features.
Delusional disorder: ≥1 delusion for ≥1 month with preserved function and behavior that is not bizarre; schizophrenia criteria are never met.
Positive symptoms (mesolimbic dopamine excess) respond to antipsychotics; negative symptoms (5 A's, mesocortical deficit) respond poorly and drive disability.
First episode → a single atypical for a 4–6 week trial; clozapine only after ≥2 failed trials (it also reduces suicide) with ANC monitoring for agranulocytosis.
EPS by onset: dystonia (hours–days) → benztropine or diphenhydramine; akathisia (days–weeks) → propranolol; parkinsonism (weeks) → benztropine or amantadine; tardive dyskinesia (months–years) → VMAT2 inhibitor.
NMS = fever, lead-pipe rigidity, autonomic instability, confusion, very high CK over days → stop the drug, cool, give dantrolene or bromocriptine; serotonin syndrome is faster, with clonus and hyperreflexia.
High-potency typicals → EPS and hyperprolactinemia; low-potency → anticholinergic effects and hypotension; olanzapine and clozapine are the worst metabolic offenders (monitor weight, glucose, lipids).

Schizophrenia: criteria and symptom domains

Diagnostic criteria. Schizophrenia requires ≥2 of 5 core symptoms (delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, negative symptoms) for at least 1 month, and at least one must be delusions, hallucinations, or disorganized speech. Continuous signs of disturbance must last ≥6 months, with decline in work, relationships, or self-care.

2 of 5core symptoms, one of them delusions, hallucinations, or disorganized speech

1 monthof full active-phase symptoms

6 monthstotal disturbance, which may include prodromal or residual phases

Positive vs negative symptoms. Positive symptoms (hallucinations, delusions, disorganization) reflect mesolimbic dopamine excess from D2 overactivity and respond well to antipsychotics. Negative symptoms, the 5 A's (Affective flattening, Alogia, Avolition, Anhedonia, Asociality), reflect a mesocortical dopamine deficit, respond poorly to drugs, and drive long-term disability.

Exclude secondary psychosis. Before diagnosing a primary psychotic disorder, rule out substances (stimulants, PCP, cannabis, hallucinogens, alcohol withdrawal), medications (corticosteroids, levodopa), delirium, and medical or neurologic disease (thyroid disease, temporal lobe epilepsy, brain tumor, HIV, syphilis). Obtain urine toxicology and basic labs, and image the brain when there are focal or atypical features.

Course. Onset is typically in the late teens to early 20s in men and somewhat later in women. Prognosis is better with later, acute onset, a clear precipitant, prominent positive or mood symptoms, and good premorbid function; it is worse with insidious onset and prominent negative symptoms.

The psychotic spectrum: timing and mood

Same picture, graded by time. Brief psychotic disorder lasts 1 day to under 1 month with full return to baseline, often after a stressor; schizophreniform disorder lasts 1 to 6 months; schizophrenia lasts 6 months or more. The relationship between psychosis and mood episodes separates the rest.

Sorting the psychotic disorders

Disorder	Duration	Distinguishing feature
Brief psychotic disorder	1 day to <1 month	Full return to baseline; often follows a stressor
Schizophreniform disorder	1 to 6 months	Schizophrenia-type symptoms; functional decline not required
Schizophrenia	≥6 months	At least 1 month active phase plus functional decline
Schizoaffective disorder	Mood episode plus ≥2 weeks of psychosis alone	Delusions or hallucinations persist ≥2 weeks WITHOUT prominent mood symptoms
Mood disorder with psychotic features	Psychosis only during mood episodes	No psychosis outside depression or mania
Delusional disorder	≥1 month	≥1 delusion; function not markedly impaired, behavior not bizarre; schizophrenia criteria never met

Schizoaffective vs psychotic mood disorder. Schizoaffective disorder is a major mood episode (depression or mania) concurrent with schizophrenia-criteria psychosis, PLUS at least 2 weeks of delusions or hallucinations with no prominent mood symptoms, and mood episodes are present for the majority of the total duration of the illness. If psychosis occurs ONLY during mood episodes, the diagnosis is a mood disorder with psychotic features.

Delusional disorder spares the rest of life: a man convinced for months that his wife is unfaithful may otherwise work and function normally. Subtypes are persecutory, jealous, erotomanic, grandiose, and somatic.

Antipsychotic choice and pharmacology

First episode. Start a single second-generation (atypical) antipsychotic such as risperidone, olanzapine, quetiapine, or aripiprazole; atypicals carry lower EPS risk than typicals. Give an adequate 4–6 week trial at a therapeutic dose before switching. Long-acting injectables help when adherence is poor.

Dopamine pathways. All antipsychotics block D2. Mesolimbic blockade treats positive symptoms, but nigrostriatal blockade causes extrapyramidal symptoms (EPS) and tuberoinfundibular blockade raises prolactin (galactorrhea, amenorrhea, gynecomastia, sexual dysfunction). Atypicals add 5-HT2A antagonism, which lowers EPS risk.

Antipsychotics at a glance

Group	Examples	Signature adverse effects
High-potency typicals	Haloperidol, fluphenazine	More EPS and hyperprolactinemia
Low-potency typicals	Chlorpromazine, thioridazine	Anticholinergic, antihistamine (sedation), α-blocking (orthostasis); thioridazine: QT prolongation, retinal deposits; chlorpromazine: corneal deposits
Atypicals	Risperidone, olanzapine, quetiapine, aripiprazole, ziprasidone, lurasidone	Weight gain, hyperglycemia, dyslipidemia; risperidone raises prolactin most
Clozapine	Reserved for treatment resistance	Agranulocytosis (~1%), myocarditis, seizures, metabolic effects, sialorrhea, constipation/ileus

High potency = high EPS; low potency = low blood pressure and a heavy anticholinergic load.

Clozapine is reserved for treatment-resistant schizophrenia, defined as failure of ≥2 adequate antipsychotic trials, and it also reduces suicidality. Because of agranulocytosis, it requires regular absolute neutrophil count (ANC) monitoring, historically enforced through a REMS program.

Metabolic monitoring. Olanzapine and clozapine cause the most weight gain, hyperglycemia, and dyslipidemia; aripiprazole, ziprasidone, and lurasidone are more weight-neutral. Track weight or BMI, fasting glucose, and lipids at baseline and during therapy.

Movement reactions and NMS

Acute dystoniaHours to days.
AkathisiaDays to weeks.
ParkinsonismWeeks.
Tardive dyskinesiaMonths to years.

EPS onset after starting the drug

Antipsychotic reactions and their treatment

Reaction	Features	Treatment
Acute dystonia	Sustained spasm: torticollis, oculogyric crisis; typical after high-potency agents	Benztropine or diphenhydramine (anticholinergic)
Akathisia	Motor restlessness, inability to sit still; easily mistaken for agitation	Lower the dose; add propranolol or a benzodiazepine
Parkinsonism	Bradykinesia, rigidity, tremor, masked facies	Benztropine or amantadine
Tardive dyskinesia	Choreoathetoid orofacial movements (lip-smacking, tongue thrusting)	Reduce or switch the drug; add a VMAT2 inhibitor (valbenazine, deutetrabenazine)
Neuroleptic malignant syndrome	High fever, lead-pipe rigidity, autonomic instability, altered mental status, very high CK, leukocytosis; evolves over days	Stop the antipsychotic; cooling and supportive care; dantrolene or bromocriptine

Tardive dyskinesia can be irreversible, and anticholinergics may WORSEN it, the opposite of acute dystonia. Never increase the antipsychotic to mask TD.

NMS vs serotonin syndrome. NMS follows dopamine blockade (or abrupt withdrawal of dopaminergic drugs such as levodopa) and develops over days with lead-pipe rigidity and sluggish reflexes. Serotonin syndrome develops faster, within hours of a serotonergic drug, with clonus, hyperreflexia, and diarrhea, and is treated with cyproheptadine. Both are emergencies requiring the offending drug to be stopped.