Low Field Magnetic Stimulation: Imaging Biomarkers in Geriatric Bipolar Depression

In this study, the investigators will examine changes in brain activity from Low Field Magnetic Stimulation in subjects over the age of 50 with bipolar disorder who are currently depressed using functional Magnetic Resonance Imaging. Following screening visits, study procedures include two visits, at least two weeks apart, during which subjects will complete brief mood scales, undergo up to 15 minutes of imaging, receive 20 minutes of Low Field Magnetic Stimulation treatment, and then return to the scanner to undergo up to 15 minutes of imaging procedures. Due to the crossover design, subjects receiving active treatment during the first visit will receive sham treatment during the second visit; subjects receiving sham treatment during the first visit will receive active treatment during the second visit. A follow-up phone call will occur at least two days after each imaging/treatment visit. The main endpoint of this study is the observation of changes in resting state functional Magnetic Resonance Imaging activity in post-treatment acquisitions as compared to pre-treatment acquisitions.