Subjects will be paid $30 for each visit and given $2 restaurant coupons. Parking tokens ($3) or bus passes ($2) will also be provided. Concomitant medications will be managed with an algorithm that discourages but, if necessary, allows changes in other psychiatric medications. At the completion of 10 weeks of blinded therapy participants in both groups will be offered 4 weeks of open-label therapy either continuing at the week 10 dose in those on active medication or slowly titrated upward for those on placebo. Participants will be assessed with the HRSD, QIDS-SR, YMRS, CCQ and drug use quantified at biweekly appointments with the RAVLT and STROOP also administered at week 14 exit. Participants will not be paid for participation in the open-label phase but bus tokens and parking passes will be provided.