Risperidone Versus Olanzapine for Mania in Preschool Children 4 to 6 Years of Age With Bipolar Disorder

Risperidone and olanzapine are atypical neuroleptics marketed for the treatment of psychotic disorders in adults. These medicines are called atypical neuroleptics because of their unique pharmacological profile, which include both D2 and 5HT2 antagonistic effects. The combined dopaminergic and serotonergic activity seems to be associated not only with antipsychotic effects, but also with mood stabilizing, mood elevating and tardive dyskinesia. The anti-climactic effects of this class of drugs led to the recent FDA approval of olanzapine as monotherapy for adult bipolar disorder. The study will consist of 8 week, open-label treatment period with random assignment to two determined treatment arms, risperidone or olanzapine. We plan to enroll 5 subjects for each arm. During the 8 weeks of treatment, patients will be seen at weekly intervals and receive study medication. At each week, measures of safety and efficacy will be obtained. Two teams of clinicians will see the patient at each visit. Team 1 will be the treating team, adjusting medication dosages and determining the safety of continuation in the study for the patient. Team 2 will be blind to the randomization status of the patient and will assess clinical improvement using the efficacy measures. For patients who have completed the 8-week acute phase without adverse event and have not responded to the medication they were assigned to will be allowed to then take part in additional 8-week trial with the other medication. At the end of the 8 weeks, patients who responded to their assigned treatment will be eligible to be enrolled and invited to participate in a separate10 month continuation study.