An open label follow-up study on amisulpride in the add-on treatment of bipolar I patients

BACKGROUND Atypical antipsychotics are widely used in the treatment of bipolar disorders. Amisulpride is an atypical antipsychotic that has been proven to be effective in treatment of schizophrenia, major depressive disorder and, more recently, acute mania. At the moment, however, no study has assessed the effectiveness of this compound in maintenance therapy of bipolar disorders. The purpose of this study was to assess the long-term effectiveness of amisulpride in combination with standard treatments in patients with bipolar I disorder who have shown inadequate responses to ongoing standard therapies. METHODS The study enrolled fourteen bipolar I outpatients, not responding to ongoing standard therapy. Three patients discontinued treatment but 11 were followed-up for 11.7 +/- 8.2 months before (range 3-24 months) and 5.2 +/- 2.7 months after the introduction of amisulpride (range 3-9 months). Relapse rates before and during treatment with amisulpride were calculated in accordance to an increase of 1 or more in Clinical Global Impressions Scale-Bipolar Version (CGI-BP) score that was accompanied by a change in therapy or to an exacerbation of the symptoms that required hospitalization. RESULTS A statistically significant decrease in overall relapse rate was observed during the period of amisulpride therapy compared with months previous to the introduction of amisulpride. The relative risk of relapse in the absence of amisulpride therapy was 3.1 (chi2 = 4.2, P < 0.05). Similarly, the rates of manic/mixed and depressive relapse were decreased but only manic episodes reached statistical significance (RR = 5.3, chi2 = 5.2, P < 0.02). DISCUSSION AND CONCLUSION This open-label study suggests that long-term therapy with amisulpride may benefit patients by improving global symptoms of bipolar disorder and reducing the rate of manic/mixed relapses. Large, randomized, double-blind, placebo-controlled studies are needed to explore the benefits of adding long-term amisulpride to standard therapies for bipolar disorder.