Initial clinical evidence suggests that the omega-3 fatty acids EPA (eicosapentaenoic acid) and/or DHA (docosahexaenoic acid) may play a therapeutic role in the management of mood disorders. EPA is an essential fatty acid, which can be metabolized to DHA and is a component of the human diet if fish is consumed. Aripiprazole is a novel second general antipsychotic that seems to function as a partial agonist at the dopamine D2 and serotonin 5-HT 1A receptors as well as an antagonist at the serotonin 5-HT 2A receptor. Since it has a favorable adverse event profile in adults, it is an attractive choice for the treatment of youth with bipolar disorder if proven efficacious. Although pilot research showed that omega-3 fatty acids monotherapy treatment resulted in improvement of manic symptoms, the improvement is less dramatic than that observed in trials of antipsychotics. We will test the safety and efficacy of omega-3 fatty acids versus placebo as an adjunctive treatment to open-label aripiprazole in children and adolescents with bipolar disorder.