Inclusion Criteria:

• DSM-IV diagnostic criteria for any bipolar disorder (type I, type II, and NOS) (diagnosed with the use of the Structured Clinical Interview for DSM-IV-TR Mood Module (SCID Mood Module)
• Written informed consent
• Men or women aged 18-65
• A baseline Hamilton-D 17 score of < 10 at screen and baseline visits.
• A baseline YMRS score of < 10 at screen and baseline visits.
• No acute episodes of depression or mania for the previous 12 weeks.
• MGH Cognitive and Physical Functioning Scale: Cut-off : >15 or Everyday Cognition Self-Report Form: Average of all items >1.5 or RBANS: <12 years education, RBANS total scale score of <85 =12 years education, RBANS total scale score of <93 >12 years education, RBANS total scale score of <100
• Able to read and understand English.

Exclusion Criteria:

Patients meeting any of the following criteria will be excluded from the study:

• Subjects with suicidal ideation where outpatient treatment is determined unsafe by the study clinician. These patients will be immediately referred to appropriate clinical treatment.
• Pregnant women, nursing mothers, or women of childbearing potential who are not using a medically accepted means of contraception (defined as oral contraceptive pill or implant, condom, diaphragm, spermicide, IUD, s/p tubal ligation, partner with vasectomy).
• Serious or unstable medical illness, including liver impairment, kidney impairment, cardiovascular, hepatic, respiratory, endocrine, neurologic or hematologic disease.
• History of seizure disorder, brain injury, any history of known neurological disease (multiple sclerosis, degenerative disease such as ALS, Parkinson disease and any movement disorders, etc).
• History or current diagnosis of the following DSM-IV psychiatric illness: organic mental disorder, schizophrenia, schizoaffective disorder, delusional disorder, psychotic disorders not otherwise specified, major depressive disorder, patients with substance dependence disorders, including alcohol, active within the last 12 months.
• History of multiple adverse drug reactions.
• Patients with mood congruent or mood incongruent psychotic features within the last 12 months.
• Clinical or laboratory evidence of hypothyroidism.
• Patients who have had an episode of acute depression or mania during the 12 weeks prior to enrollment.
• Patients who have had electroconvulsive therapy (ECT) within the 6 months preceding enrollment.
• Patients taking drugs which alkalinize the urine (e.g., carbonic anhydrase inhibitors, sodium