Ketogenic and Nutritional Interventions for First Episode Bipolar Disorder

This is a randomized, controlled clinical trial to assess the effects of the ketogenic diet in combination with treatment as usual on brain energy metabolism and psychiatric symptoms in individuals with first episode bipolar disorder and schizoaffective disorder.

Inclusion Criteria: * Between the ages of 18 and 45. * Ability to adhere to study diets. * Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) diagnosis of bipolar I disorder or schizoaffective disorder with onset of illness in the last 7 years. * Must have a stable psychiatric disorder with no change in psychiatric medications within the past 2 weeks of screening * Must not be expected to require addition of any new psychiatric medications during the 12-week duration of the study. Exclusion Criteria: * Unable to sign informed consent * Contraindication to magnetic resonance (MR) scan (including claustrophobia) * Unstable medical illness (including cardiovascular, hepatic, renal, respiratory, endocrine, neurological, or hematological disease) * Current DSM-5 substance use disorder * Currently pregnant, nursing, or of childbearing potential and not using a medically accepted means of contraception * Have a body weight of over 350 lbs or a body mass index (BMI) \