Acute and long-term effectiveness of clozapine in treatment-resistant psychotic depression.

The treatment of refractory major depression, including the psychotic subtype, is a therapeutic challenge. Three cases of resistant psychotic depression were treated with clozapine monotherapy, an atypical antipsychotic drug effective in treatment-resistant schizophrenia and mania. Both psychotic and mood symptoms responded well to clozapine monotherapy, although response was delayed in one case. Tardive dyskinesia improved markedly, and tardive dystonia improved moderately in one patient. No patient relapsed during a follow-up period of 4-6 years of clozapine treatment. Clozapine was well-tolerated with few side effects. These observations suggest controlled trials of clozapine in the treatment of psychotic depression that fails to respond to electroconvulsive therapy or typical neuroleptics plus tricyclic antidepressants are indicated. The same is true for the use of clozapine in maintenance treatment for psychotic depression in those cases in which typical neuroleptic drugs are required, in order to reduce the risk of tardive dyskinesia and dystonia.