Long-term risperidone treatment in bipolar disorder: 6-month follow up

Antipsychotic agents, such as clozapine and risperidone, have been reported to be beneficial in the treatment of some bipolar patients. Many bipolar patients experience `breakthrough episodes' of mood disorder, with mania or depression recurring despite adequate ongoing levels of one or more mood-stabilizing medications. There are no controlled studies of breakthrough episodes, and there is little open experience to guide clinicians in pharmacotherapy of breakthrough episodes. This report describes the outcome of adjunctive risperidone treatment in breakthrough episodes of bipolar disorder. We assessed the outcome of openly adding risperidone to the medication regimen of 12 outpatients with bipolar disorder, type I, who suffered breakthrough episodes despite adequate maintenance medication (lithium, valproate, or carbamazepine, or a combination of these). Prospective ratings were made at each clinical visit using the Clinical Global Impressions and Global Assessment of Functioning scales. Patients received risperidone for a mean of 6.0 months (23.96 weeks, range 0.5-72 weeks) at a mean dose of 2.75 mg/day (range 1-4.5 mg/day). Four patients discontinued medication (two because of lack of efficacy at weeks 6 and 64, and two because of adverse events at weeks 0.5 and 23). Among the remaining eight patients, four experienced a 10-25 point improvement in Global Assessment of Functioning scores and were rated much better on the Clinical Global Impression-Improvement scale. Although one patient suffered a major depressive recurrence (at week 22), no patient experienced worsening of mania. This small open series suggests a subgroup of bipolar patients with breakthrough episodes may benefit from treatment with risperidone.