IS CLOZAPINE A MOOD STABILIZER

Background: Clozapine has been increasingly shown to be effective in t he acute and maintenance treatment of bipolar disorders. For this reas on, we studied whether clozapine alone is effective as a mood stabiliz er in patients with refractory bipolar disorders. Method: Subjects wer e part of a long-term follow-up study cohort of 193 patients with refr actory mood disorders who were treated with clozapine at McLean Hospit al prior to July 1, 1992. Patients included in this study were those o lder than 16 years with bipolar disorder (manic or mixed) and schizoaf fective disorder, bipolar type, discharged taking clozapine alone (N = 17). Hospital records on all patients were reviewed by trained raters blind to ''best-estimate'' diagnoses. Response to clozapine was deter mined by the Clinical Global Impressions-Improvement (CGI-I) scale. Pa tients were contacted at least 6 months after clozapine initiation for semistructured follow-up interviews by raters blind to diagnosis and baseline information. Results: Seventeen subjects were contacted 16.1 +/- 5.6 months after clozapine initiation. Most of the 17 patients had previously failed trials of lithium, valproate, carbamazepine, neurol eptics, combinations of these, and electroconvulsive therapy; or had t ardive dyskinesia. Of these patients, 65% (11/17) continued to be on c lozapine therapy alone at follow-up and had no subsequent rehospitaliz ation or affective episode. At follow-up, there was a significant decr ease in the rehospitalization rate (p =.025) than before starting cloz apine and a significant improvement in CGI-I scores (p =.02). Conclusi on: Clozapine monotherapy is an effective mood stabilizer, reducing bo th the number of affective episodes and rehospitalizations in patients with severe refractory bipolar illness.