Long-term effect on outcome of clozapine in chronic therapy-resistant schizophrenic patients

Controlled clinical trials have shown that the atypical neuroleptic clozapine is highly effective in schizophrenic patients who are unresponsive to conventional neuroleptic agents. The long-term outcome of clozapine treatment was studied in 122 patients who were treated between 1974 and 1991. The mean duration of treatment was 5.2 years. At follow-up, 74 patients (61%) were still receiving clozapine. Only 11 patients discontinued treatment because of adverse events and eight because of poor compliance. Clinical improvement was seen in 87% of patients; 40% had resumed employment after 2 years' treatment. About one-third of patients who received clozapine for 5-10 years continued to improve during this time; this was probably because of a continuing process of socialisation. Thus, clozapine offers important advantages in schizophrenic patients resistant to conventional neuroleptics in terms of long-term efficacy and lack of extrapyramidal side-effects.