Targeting Cognition in Bipolar Disorder With Pramipexole

All eligible participants will undergo study visits at screening, baseline (week 0), week 1, week 2, week 3, week 4, week 6, week 8, and week 12, (end of study). Randomization will be conducted via a computer generated program and all study staff will be blinded unless un-blinding is required for safety reasons. Subjects will be randomized on a 1:1 ratio with stratification for concomitant antipsychotic status and depression at baseline (HRSD \<8 vs \> 8). Study drug will be blinded and matched to placebo. Adapting from our previous work in BD and according to package labeling, the dosage titration schedule will be slow and flexible. Dosing will be initiated at 0.25 mg QHS on night one, followed by 0.25 mg BID day two onward, and increased every week to a target of 4.5 mg/day. As compared with our previous maximum 1.5 mg/day (Burdick et al. 2012), we opted to allow up to 4.5 mg/day (the maximum approved dosage in Parkinson's disease) to ensure adequate target engagement. We are familiar with this dose range, as 4.5 mg/day was allowed in our study in BD depression (Goldberg et al. 2004). Dosing will be flexible based on side effects; however, if 1.5 mg/day cannot be tolerated, the subject will be discontinued. Titration will occur up to week 6 and then efforts will be made to maintain the same dose until the completion of the trial (week 12).