Reward-Related Brain Activity in Bipolar Disorder and Depression: A Quest for the Test

The proposed pilot study is the first systematic investigation of reward-related brain activity as a possible biological marker of differential risk for Bipolar Disorder versus unipolar depression. We predict that Bipolar Disorder symptoms will be uniquely associated with abnormally elevated reward-related brain activity, whereas unipolar depression symptoms will be uniquely associated with abnormally reduced reward-related brain activity. The subsequent NIMH application for which this proposal will provide pilot data will examine this hypothesis on a much larger scale. Specifically, we will examine the relationship between reward-related brain activity and bipolar and depressive symptom onset, course, and severity over a multi-year follow-up period.