Catatonia: diagnosis, classification, and treatment.

Catatonia is a distinct neuropsychiatric syndrome that is becoming more recognized clinically and in ongoing research. It occurs with psychiatric, metabolic, or neurologic conditions. It may occur in many forms, including neuroleptic malignant syndrome. Treatment with benzodiazepines or electroconvulsive therapy leads to a dramatic and rapid response, although systematic, randomized trials are lacking. An important unresolved question is the role of antipsychotic agents in treatment and their potential adverse effects.