Objective. To compare clinical responses of patients with pediatric bipolar disorder being treated with risperidone versus divalproex.
Methods. Medical records of outpatients younger than 18 years of age were reviewed to gather data on those who received risperidone or divalproex monotherapy for the treatment of bipolar disorder. Effectiveness was assessed using the Clinical Global Impressions Severity (CGI-S) and Improvement (CGI-I) scales assigned by the treating clinician at visits during the initial 3 months of treatment with risperidone or divalproex. Change in CGI-S score over time was the primary outcome variable. The number of patients with a CGI-I score of ≤ 2 at endpoint who did not discontinue the index medication because of adverse events was also compared.
Results. A total of 28 patients aged 5-14 years who were being treated for bipolar disorder were identified (risperidone n = 16; divalproex n = 12). Regression analysis of change in CGI-S scores revealed greater reductions in bipolar symptoms (p = 0.022) and a faster reduction in CGI-S scores (p = 0.016) in patients receiving risperidone than divalproex. A significantly shorter time to achieving a CGI-I score of ≤ 2 was observed with risperidone than divalproex (26.8 ± 20.7 days vs. 33.8 ± 11.3 days; p = 0.048). However, the proportion of patients with a CGI-I score ≤ 2 at endpoint was not significantly different (risperidone 69% versus divalproex 42%, p = 0.250). Three patients discontinued risperidone and 2 discontinued divalproex. Of these, none of the patients treated with risperidone and only 1 patient treated with divalproex discontinued treatment because of a documented adverse event. Risperidone was associated with significantly more weight gain then divalproex at 3 months (risperidone 2.46 ± 1.16 kg versus divalproex 0.43 ± 0.77 kg, p = 0.034).
Conclusions. Patients receiving risperidone experienced a faster decrease in the severity of their bipolar symptoms, as measured by faster decreases in CGI-S scores, than did those who received divalproex. However, risperidone was also associated with significantly greater weight gain.