Bipolar Study of Seroquel XR With Pramipexole Dihydrochloride

Quetiapine is a first-line option in Canadian guidelines for the treatment of bipolar depression; however, there is room for improvement as the remission rate is approximately 50% and the response rate is approximately 60%. Pramipexole, which is currently used to treat Parkinson's disease and restless legs syndrome, is reported to have antidepressant effects in patients with unipolar or bipolar depression. There are no other clinical studies to evaluate the efficacy of pramipexole combined with an atypical antipsychotic, such as quetiapine XR, in the treatment of bipolar depression. This study is a multicentre, randomized, double-blind and placebo-controlled exploratory study in which patients will receive one of three treatment arms for a treatment period of 16 weeks: quetiapine XR plus placebo, quetiapine XR plus 0.25mg pramipexole, or quetiapine XR plus 0.50mg pramipexole.