Clinical outcomes of patients with bipolar disorder in the manic phase on valproate and olanzapine versus valproate and risperidone

Abstract Purpose Previous studies have shown that combining mood stabilizers and atypical antipsychotics is more effective than either treatment alone in bipolar disorder. The comparison of the two combinations is limited. We aim to compare the efficacy and adverse drug reactions of valproate plus olanzapine or risperidone combination treatment in the bipolar disorder, manic phase. Method In this 4-week study, 60 patients with DSM-V bipolar disorder in the psychotic manic phase were included and divided into either valproate plus olanzapine (n = 30) or risperidone (n = 30). The primary outcome was measured by the difference in mean total scores on the Young Mania Rating Scale (YMRS) and the Positive and Negative Syndrome Scale (PANSS). The secondary outcome for adverse effects was measured using the Naranjo ADR Probability Scale. The mean values obtained at weeks 0, 2, and 4 were compared. Results In our study, the mean difference in YMRS scores from baseline to week 4 in the olanzapine and risperidone groups was 13.9331.202 and 10.7671.164, respectively. These scores manifest significant changes within and between groups (p = < 0.001). A greater reduction was observed in the olanzapine group. There was no trend in the reduction of PANSS mean values between the groups, but a significant difference within the groups. However, a reduction was noted in the risperidone group. Adverse effects were observed more frequently during co-therapy with risperidone. Although, weight gain was notable in the olanzapine group. Conclusion All the results of our study showed that olanzapine in combination with valproate has slightly higher efficacy than risperidone.