Ketogenic and Nutritional Interventions for First Episode Bipolar 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) \<20
* Score above 15 on the Young Mania Rating Scale (YMRS)
* History of significant head injury
* Current cancer diagnosis
* Current diagnosis of type 1 or type 2 Diabetes Mellitus
* History of gastric bypass surgery or any weight loss surgery
* Concomitant treatment with Propofol
* Familial hypercholesterolemia