Ketogenic Metabolic Therapy in Schizophrenia, Bipolar Disorder, Major Depressive Disorder: Deep Omic Profiling

Inclusion Criteria: 1. diagnosed with bipolar disorder (BD), major depressive disorder (MDD), and or schizophrenia 1. For individuals diagnosed with bipolar disorder (BD): * Meet DSM V criteria for BD (any subtype) * Not mild * \>40 on BPRS * clinically stable (with no hospitalization for past 3 months) 2. For individuals diagnosed with major depressive disorder (MDD): * Not mild * PHQ-9 \> 10 * clinically stable (with no hospitalization for past 3 months) 3. For individuals diagnosed with schizophrenia: * Meet DSM V criteria for schizophrenia (any subtype) * Not mild * \>40 on BPRS * clinically stable (with no hospitalization for past 3 months) 2. Participants may currently be on a stable and adequate dose of SSRI antidepressant therapy or other psychiatric medication. Concurrent hypnotic therapy (e.g., with zolpidem, zaleplon, melatonin, or trazodone) will be allowed if the therapy has been stable for at least four weeks prior to screening and if it is expected to remain stable. Participants may be switched from other classes of medication to another medication class by their psychiatrist or primary care doctor, but need to be stable enough to enroll and adhere to study procedures. 3. willing and able to give informed consent for participation in English. 4. live within the United States. \-------------------------------------------------------------------------------- Exclusion Criteria: 1. has started the ketogenic diet or was in ketosis within 3 months of wanting to enroll 2. pregnant or nursing 3. insulin dependent 4. comorbidity of developmental delay 5. in a current severe mood or psychotic state when entering the study that would prohibit compliance with study visits or dietary programs. 6. any one who has been hospitalized or taken clozapine at doses above 550mg over the past 3 months 7. inability to complete baseline measurements 8. severe renal or hepatic insufficiency 9. cardiovascular dysfunction, including diagnosis of: * Congestive heart failure * Angina * Arrhythmias * Cardiomyopathy * Valvular heart disease 10. active substance abuse with illicit drugs or alcohol and/or current diagnosis of a Substance Use Disorder (Abuse or Dependence, as defined by DSM-IV-TR), with the exception of nicotine or cannabis dependence 11. active suicidal and considered at significant risk for suicide during course of study 12. participation in any clinical trial- within the past month or concurrent to study participation- with an investigational drug/device and/or intervention that may interfere with study participation/evaluation of results 13. mild BPRS at screening or baseline visits 14. history of TBI 15. any other medical condition that may make diet intervention dangerous as determined by the study medical team (e.g. anorexia nervosa) or assessed by study team to have insufficient control over their food intake to adhere to study diets. 16. any medical condition that physicians or the PI believe would interfere with study participation or evaluation of results 17. history of familial hypercholesterolemia