Randomized, placebo-controlled trial of risperidone for acute treatment of bipolar anxiety

BackgroundThe treatment of bipolar disorder is often complicated by the presence of a co-occuring anxiety disorder. Although second generation antipsychotics are being used with increasing frequency in bipolar patients, their anxiolytic effects have not been well studied in this population.MethodsThe anxiolytic effect of risperidone 0.5–4 mg/day was tested in an 8-week, double-blind, placebo-controlled, randomized clinical trial in 111 patients with bipolar disorder and a co-occuring panic disorder or generalized anxiety disorder (GAD). The primary outcome measure was the Clinician Global Improvement-21 Anxiety scale (CGI-21 Anxiety). Secondary measures included the Hamilton Anxiety Scale (HAM-A) and the Sheehan Panic Disorder Scale.ResultsOn the last-observation-carried forward analysis of repeated measures analysis of variance (ANOVA), risperidone was not more effective than placebo for the CGI-21 Anxiety score or the other anxiety outcome measures. Risperidone was well tolerated, with only two patients withdrawing because of adverse events.LimitationsThe risperidone treated group had more patients with mixed states and lifetime panic disorder at randomization than the placebo group. The study was limited to 8 weeks and to individuals with bipolar and comorbid panic disorder or GAD. The results may not be applicable to risperidone as an add-on treatment to mood stabilizers, or to bipolar disorder comorbid with anxiety disorders other than panic disorder or GAD.ConclusionsRisperidone monotherapy was not an effective anxiolytic for bipolar patients with comorbid panic disorder or GAD in doses of 0.5–4 mg/day over 8 weeks of treatment. The efficacy of other second generation antipsychotics and mood stabilizers on anxiety in patients with bipolar disorder and a co-occuring anxiety disorder should be investigated in double-blind, placebo-controlled studies.