Schizophrenia Spectrum and Other Psychotic Disorders
What this domain tests
This domain tests duration-based diagnosis, symptom domains, treatment resistance and the emergencies that follow dopamine blockade. Kuwait Board vignettes often hinge on the length of illness and on excluding mood and medical causes.
Core rules and concepts
- DSM-5-TR schizophrenia: at least two core symptoms, with at least one from delusions, hallucinations or disorganised speech; active phase of one month or more; continuous signs for at least six months; functional decline; not attributable to a substance or medical condition; mood episodes brief relative to the illness.
- Duration ladder: brief psychotic disorder under one month with full return to baseline; schizophreniform one to six months; schizophrenia six months or more.
- Symptom domains: positive, negative, cognitive, disorganised, mood.
- Treatment resistance: failure of two adequate antipsychotic trials (adequate dose, six weeks or more) - the indication for clozapine. Clozapine carries agranulocytosis risk near 1% with mandatory blood monitoring, plus early myocarditis, seizures, sialorrhoea and severe constipation.
- Catatonia: lorazepam challenge first, ECT if refractory. Neuroleptic malignant syndrome is different - rigidity, hyperthermia, raised creatine kinase, autonomic instability - and is managed by stopping the drug with dantrolene or bromocriptine.
- Prognosis: lifetime suicide risk around 5–10%; a long duration of untreated psychosis predicts worse outcome.
Worked example
A 24-year-old has four months of persecutory voices plus two years of social withdrawal and falling grades. The six-month threshold is already met through the prodromal decline, so the diagnosis is schizophrenia, not schizophreniform disorder.
Traps that cost marks
- Diagnosing schizophrenia when a mood episode is prominent and concurrent.
- Missing mimics: corticosteroids, thyrotoxicosis, autoimmune encephalitis, cannabis, delirium.
- Prescribing a second antipsychotic instead of clozapine in true resistance.