Cholinergic syndrome following anticholinergic withdrawal in a schizophrenic patient abusing marijuana.

A 27-year-old neuroleptic-stabilised schizophrenic patient presented with a three-day history of psychomotor retardation, disturbed sleep, and social and emotional withdrawal following reduction of his anticholinergic dosage; his symptoms had intensified after an increase in neuroleptic dosage, based on a diagnosis of psychotic decompensation. Recognition of a cholinergic syndrome and institution of appropriate anticholinergic treatment resulted in rapid improvement. The clinical distinction between a cholinergic overdrive state and schizophrenic exacerbation, while sometimes difficult, can be critical in selecting appropriate management.