The effect of clozapine on the course of illness in chronic schizophrenia: focus on treatment outcome in out-patients.

Forty-eight consecutive schizophrenic patients treated with clozapine (mean daily dose 436 mg) for at least 1 year (mean 7.6, range 2.2-14.8 years) were studied retrospectively. The most favourable changes in the course of illness were observed in 39 out-patients, whose duration of hospitalization per year continuously and significantly declined after the introduction of clozapine. The out-patients who continued with clozapine treatment for more than 10 years (n = 8) did not need hospitalization at all during the last year of the observation period. The improvement in social functioning in the out-patient group correlated positively with the duration of clozapine medication (r = 0.384, p = 0.016) and with the duration of hospitalization (r = 0.372, p = 0.020) after introduction of clozapine. Out-patients with disorganized schizophrenia (later called hebephrenic according to the Finish version of DSM-III) showed more noticeable clinical (U = 226, p = 0.032) and social (U = 233, p = 0.024) improvements than non-hebephrenic patients. There appears to be a subgroup of hebephrenic patients who benefit from clozapine more than patients with other types of schizophrenia.