2. Meets criteria for bipolar disorder NOS, currently in an episode of major depression, as defined by the DSM-IV (American Psychiatric Association, 1994) and documented by the use of the Structured Clinical Interview for Axis I DSM-IV Disorders (SCID-I), and by a rating of >15 on the 25-item Hamilton Rating Scale for Depression (HRSD-25). We will limit inclusion specifically to those individuals who have histories of 1) at least one short (2-3 day) hypomanic episode OR 2) at least one subthreshold hypomanic episode (at least 4 consecutive days of elevated mood and 2 of the other symptoms of hypomania or irritable mood with 3 of the other symptoms of hypomania). NOTE: Like the National Comorbidity Survey Replication, individuals whose hypomania occurred while on antidepressant medication will not be excluded from the trial (Merikangas, personal communication, 2011).