Psychosis Other Than Schizophrenia

Brief psychotic disorder — an illness lasting less than 2 weeks, dominated by hallucinations, delusions, and thought disorder.

Schizophreniform disorder — a psychotic illness with many features of schizophrenia but a shorter duration (<6 months). Rapid, full resolution predicts a better prognosis, but the disorder can progress to schizophrenia.

Delusional (paranoid) disorder — usually presents in middle-to-late adult life, characterised by delusions (grandiose, persecutory, erotomanic, or somatic). Auditory/visual hallucinations, if present, are not prominent, and impairment is less than in schizophrenia. Course is variable — either persistent symptoms or a remitting-relapsing pattern.

Schizoaffective disorder — prominent mood symptoms (elevated mood and/or depression) alongside the core symptoms of schizophrenia. Management usually combines an antipsychotic with an antidepressant (for depressive episodes) and/or lithium or sodium valproate (for manic episodes); drugs used for bipolar prophylaxis can also be used for the mood component here.

Psychotic depression:

• Psychotic features: delusions in >90% of cases, hallucinations in ~10% (roughly equal split between mood-congruent and mood-incongruent).
• Pathological guilt — ruminating over past failures/wrongdoing (ask specifically about a sense of deserving punishment).
• Profound psychomotor disturbance — the patient may be mute, making psychotic features difficult to elicit directly.
• Can mimic a pseudo-dementia picture.
• Treatment efficacy: antidepressant + antipsychotic combination ~80%; ECT ~80%; antipsychotic alone ~33%; antidepressant alone ~25%; placebo ~5%.