Psychotic Disorders
Core concepts
Know the DSM-5/ICD-11 criteria for schizophrenia, schizophreniform disorder, brief psychotic disorder, schizoaffective disorder, delusional disorder, and substance/medication-induced psychosis. Duration criteria: brief psychotic disorder (1 day–1 month), schizophreniform (1–6 months), schizophrenia (>6 months). Schizoaffective disorder requires psychotic symptoms for ≥2 weeks in the absence of mood symptoms, plus mood episodes for the majority of the illness.
Management
First-line antipsychotics are chosen on side-effect profile. Clozapine is indicated for treatment-resistant schizophrenia (failure of ≥2 adequate trials) and reduces suicide risk; monitor for agranulocytosis, myocarditis, and seizures. Address metabolic monitoring, tardive dyskinesia (consider VMAT2 inhibitors), and neuroleptic malignant syndrome (rigidity, hyperthermia, autonomic instability, raised CK).
Traps
- Diagnosing schizophrenia in the presence of prominent mood symptoms without checking the temporal relationship.
- Missing a first-episode organic screen (drugs, autoimmune encephalitis, temporal lobe epilepsy).
- Forgetting clozapine in a treatment-resistant case or in persistent suicidality.
- Confusing catatonia (treat with benzodiazepines/ECT) with negative symptoms.
Rule of thumb
In any first-episode psychosis: urine toxicology, full blood count, thyroid, electrolytes, glucose, and consider neuroimaging if focal signs or atypical features.