Ketogenic Diet May Improve Symptoms and Cognition in Schizophrenia and Bipolar Disorder: Study

The study group included outpatients who were identified as having been diagnosed with schizoaffective disorder or bipolar 1 disorder and was randomly allocated to either a strict ketogenic diet cohort (KETO) or a diet-as-usual control cohort (DAU) during a 1-month baseline period. Halfway through the trial, researchers modified the study design in order to give patients from both cohorts an option to continue in the ketogenic protocol in an extended phase of the study, thus forming a longitudinal sub-group of participants who successfully adhered to the nutritional regimen for 4 months.

The scientific group carefully gathered objective biological and clinical tracking parameters at various operational time points, comparing differences in metabolic biomarkers, symptom intensity, and cognitive test performance between KETO and DAU cohorts at 1 month and longitudinal changes compared to baseline levels at 4 months of ketosis.

Key findings:

• Randomization of the first cohort was done effectively, with exactly 28 individuals allocated to KETO and 30 individuals allocated to the DAU control group.
• This modified procedure permitted a sub-cohort of 25 patients to complete an uninterrupted 4-month period on the ketogenic therapy.
• As compared with DAU, KETO patients experienced reduced weight (Padj < .001), hemoglobin A1c (Padj = .05), and insulin resistance (Padj = .05).
• At the end of the 4 months of continued ketosis, patients made substantial gains in terms of all three symptom categories (positive, negative, depressive; all P < .001).
• Cognitive function tests administered at the 4-month time point showed significant improvement in cognitive scores compared to the baseline measures (P < .001).
• Increased levels of blood ketones were significantly associated with correction of the prediabetes indicators and alleviation of depressive symptoms (all P < .001).
• Weight loss showed no statistical association with metabolic or symptom measures.

To conclude, patients with schizophrenia and bipolar-1 disorder experienced an improvement in their metabolism, cognitive functioning, and symptomatology while on the ketogenic diet regimen. The results obtained during the clinical trial serve as an empirical basis for the newly developing area of metabolic psychiatry, which demonstrates that dietary management may safely and efficiently fix medication-caused metabolic disorders without worsening psychiatric disorders.

Reference:

Samantha V Abram, Juliette M Kyner, An Vu, Zanib Naeem, Shebani Sethi, Michael S Jacob, Susanna L Fryer, Daniel H Mathalon, Judith M Ford, Metabolic Improvements with a Ketogenic Diet Correlate with Symptom Improvement in Psychosis: A Randomized Controlled Trial, Schizophrenia Bulletin, Volume 52, Issue 4, July 2026, sbag082, https://doi.org/10.1093/schbul/sbag082