Open-label, 8-week trial of olanzapine and risperidone for the treatment of bipolar disorder in preschool-age children

Background: To evaluate short-term safety and efficacy of atypical antipsychotics in a single-site, prospective, open-label, 8-week study of risperidone and olanzapine monotherapy in preschoolers with bipolar disorder (BPD). Methods: Risperidone was initiated at an open-label dose of .25 mg/day, increased weekly according to response and tolerability to a maximum does of 2.0 mg/day. Olanzapine was initiated at 1.25 mg/day and increased to no more than 10 mg/day. Results: Thirty-one children aged 4-6 years were treated with olanzapine (n = 15, 6.3 ± 2.3 mg/day) or risperidone (n = 16, 1.4 ± .5 mg/day). At study end point (week 8 or last observation carried forward), there was a 18.3 ± 11.9 point (t = -5.6, p < .001) reduction in risperidone-treated subjects and a 12.1 ± 10.4 point (t = -4.4, p < .001) reduction in Young Mania Rating Scale (YMRS) scores in olanzapine-treated subjects that did not differ between groups (t = 1.4, p = .2). Response criteria (Clinical Global Impression improvement of "Much" or "Very Much" improved or a YMRS change of ≥ 30% or more) indicated no difference in rate of response with risperidone and olanzapine (69% vs. 53%, χ²₍₁₎ = .8, p = .4). Conclusions: This prospective open study suggests that treatment with risperidone or olanzapine may result in a rapid reduction of symptoms of mania in preschool children with BPD. Because of substantial residual symptomatology and adverse effects, however, a pressing need exists to identify additional safe and effective treatments for the management of BPD in this high-risk population.