FMRI of Patients Receiving IV Ketamine for Treatment Resistant Bipolar Depression

Prospective open-label, single-group observational study of IV ketamine for treatment-resistant bipolar depression. All participants receive an acute series of ketamine infusions twice weekly for three weeks; responders may continue weekly infusions for three additional weeks.

Functional MRI is performed prior to the first infusion and after completion of the acute series to assess neural correlates of treatment response. Responders are defined as >=50% decrease on QIDS-SR-16 from baseline.