 Bipolar Depressed Sample: Forty subjects ages 18-55 male and female will be selected who meet DSM-IV criteria for bipolar I or II disorder and are currently depressed, with HDRS score in the moderately-to-severely depressed range greater than 18. Subjects may be inpatients or outpatients. Because effective treatment will not be discontinued for the purposes of this protocol, subjects will be identified who have never been treated or who have discontinued medication due to lack of efficacy, noncompliance, physician order or other reasons prior to study entry. 