Ketogenic diet shows early promise for psychosis beyond metabolic health

Clinical takeaway: A medically supervised ketogenic diet may emerge as a useful adjunct to standard treatment for selected patients with psychotic disorders, particularly those with significant metabolic dysfunction. Current evidence remains preliminary, and longer, fully controlled trials are needed before widespread adoption.

People with schizophrenia-spectrum and bipolar I disorders face a high burden of metabolic disease, much of it related to antipsychotic treatment. This trial suggests that a ketogenic diet may improve both metabolic health and psychiatric outcomes, although larger controlled studies are needed before routine clinical use.

In the first randomized controlled trial of ketogenic therapy in psychotic disorders, investigators assigned 58 outpatients with schizophrenia-spectrum or bipolar I disorder to either a ketogenic diet (n = 28) or their usual diet (n = 30) for 1 month. Forty-seven participants completed the randomized phase, and 25 continued the ketogenic diet for an optional 4-month extension. Adherence was high, with 83% of daily ketone measurements during the randomized phase and 94% during the extension confirming nutritional ketosis, and no significant diet-related adverse effects were reported.

After 1 month, participants following the ketogenic diet experienced greater improvements in weight, HbA1c, and insulin resistance than those receiving usual care. Higher ketone levels were also associated with lower blood glucose and reduced depressive symptoms, even after accounting for weight loss, suggesting that ketosis itself, not simply weight reduction, may contribute to the observed benefits.

Among participants who remained on the diet for 4 months, metabolic improvements were sustained and accompanied by improvements in positive and negative psychotic symptoms, depressive symptoms, and cognitive performance. As lead author Judith M. Ford, PhD, noted, "The improvement we saw in cognitive and psychological symptoms is particularly important... because current medications... don't address their overall mental wellbeing, including cognitive or depressive symptoms." The authors caution that the psychiatric and cognitive findings come from a small, uncontrolled extension and require confirmation in larger randomized trials.

Source: Abram SV, et al. (2026 July 8) Schizophr Bull. Metabolic Improvements with a Ketogenic Diet Correlate with Symptom Improvement in Psychosis: A Randomized Controlled Trial