A double-blind trial of carbamazepine in negative symptom schizophrenia.

Twenty-eight residual schizophrenics hospitalized in a chronic institution with a 9 to 30 year history of disease, with predominantly negative symptoms were given carbamazepine. Carbamazepine was administered in a double-blind trial and therapeutic effects were measured by the Scale for the Assessment of Negative Symptoms (SANS). Patients were also assessed for positive symptoms using the Brief Psychiatric Rating Scale (BPRS), for depression using the Hamilton Depression Scale, for extrapyramidal symptoms by the Simpson and Angus scale, to rule out these symptoms as sources of secondary negative symptoms. The study continued for 7 weeks with therapeutic carbamazepine levels achieved during the last 5 weeks. There was no significant positive effect of carbamazepine on negative symptoms.