Ketogenic Diet Trial Reports Metabolic And Psychiatric Gains In Psychosis

Key Takeaways

• One month of ketogenic diet versus diet-as-usual was associated with statistically significant metabolic improvement.
• Among participants who continued for four months, sustained metabolic improvement, lower depression and schizophrenia symptoms, and better cognitive performance were described.
• High ketosis maintenance and no significant side effects were reported across both trial phases.

A first randomized controlled trial of a ketogenic diet in psychotic disorders from UCSF, published in Schizophrenia Bulletin, linked one month of treatment to rapid metabolic improvement in adults with schizophrenia-spectrum or bipolar I disorders. Psychiatric and cognitive changes were reported only among participants who continued into an uncontrolled four-month extension. The trial adds to growing interest in ketogenic therapy for serious mental illness, while leaving the later observations preliminary because they came from the noncomparative follow-up period.

Participants entered an open-label randomized phase comparing a ketogenic diet with diet-as-usual over one month. The intervention was presented as an adjunctive dietary approach rather than a replacement for standard psychiatric care. The trial enrolled 58 adults, 47 completed the initial comparison, and 25 chose to continue into an optional four-month single-arm ketogenic diet extension. Without a concurrent comparator, the extension cannot distinguish changes related to time, selection, or continued participation from dietary effects alone. The study therefore separates a controlled short-term comparison from a longer descriptive follow-up period.

During the randomized month, the ketogenic diet group showed statistically significant improvement in key metabolic markers compared with the control group. Higher ketone levels were also associated with lower blood glucose and lower PHQ-9 depression symptom scores, even after accounting for weight loss. Feasibility in the controlled phase appeared high, with 83% of daily tested participants maintaining ketosis. No comparative psychiatric or cognitive improvement was reported from that month beyond the PHQ-9 association. The clearest controlled finding was metabolic, while the mood association remained correlational within that short randomized interval.

Among participants who continued for four months, metabolic improvement was sustained alongside reductions in depression and schizophrenia symptoms and better cognitive performance. Daily testing suggested ongoing adherence, with 94% of participants maintaining ketosis during the extension, and no significant side effects were reported. Judith M. Ford, who led the work, highlighted the importance of cognitive and psychological improvement in a population whose medications may not address overall mental well-being. The authors said larger, longer, fully controlled trials are needed and that the four-month psychiatric and cognitive findings require replication under controlled conditions.