Effects of Electroconvulsive Therapy (ECT) in Bipolar Depression

Inclusion Criteria: * Male or female age 18-55 * Meets DSM-IV criteria for Bipolar Disorder Type I, II, or NOS with current episode depressed * Has been scheduled to be evaluated by an ECT consultant from the McLean Hospital ECT service * Current score of greater than or equal to 24 on the Montgomery-Asberg Depression Rating Scale (MADRS) Exclusion Criteria: * Unwillingness or inability to provide informed consent * Lifetime history of schizophrenia * DSM-IV diagnosis of alcohol or substance dependence, with the exception of nicotine dependence, within three months prior to screening * Positive urine toxicology screen at screening (NOTE: Participants with a positive urine toxicology screen who are prescribed benzodiazepine, stimulant, or opiate medications by their physician will be permitted to enroll in the study as long as they do not meet abuse or dependence criteria for these substances) * Female participants with a positive urine pregnancy test at screening * Pregnancy. Females of childbearing potential must be using an effective contraceptive method (e.g., abstinence, prescription oral contraceptives, contraceptive injections, MRI-safe intrauterine device, double-barrier method, male partner sterilization) * Any contraindications to having an MRI scan, including cardiac pacemakers, metal vascular clips or stents, artificial heart valves, certain kinds of prostheses, brain stimulator devices, implanted drug pumps, ear implants, eye implants or known metal fragments in eyes, exposure to shrapnel or metal filings (wounded in military combat, sheetmetal workers, welders, and others), transdermal drug delivery systems, and certain tattoos with metallic ink. NOTE: Participants will be screened for these conditions at screening, and will be required to fill out a standard MRI screening form at the Brain Imaging Center, which will be reviewed by an MRI technician prior to each MRI scan * Scheduled to receive first ECT treatment on a Friday