A Ketogenic Diet Improves Psychosis Symptoms: What Does the New Trial Tell Us?
- Moira Newiss
- 7 days ago
- 3 min read
Very recently, the results were published from the first randomised controlled trial investigating a ketogenic diet in people with psychotic disorders, including schizophrenia-spectrum disorders and bipolar I disorder with psychotic features.
This is an important study because, although there has been growing interest in metabolic therapies for serious mental illness, much of the previous research into ketogenic diets has consisted of small pilot studies or case reports. This trial provides some of the first controlled evidence that a ketogenic diet may have benefits for both metabolic health and psychiatric symptoms.
What did the researchers find?
The first part of the trial included 58 participants, who were randomly assigned to either a ketogenic diet (28 people) or their usual diet (30 people) for one month.
The ketogenic diet was designed to induce nutritional ketosis, and adherence was monitored using blood ketone measurements. The average ketone level was around 1.28 mmol/L, with 83% of participants remaining in ketosis throughout this initial period.
After just one month, the ketogenic group experienced improvements in several measures of metabolic health, including body weight, HbA1c and insulin resistance. There were also improvements in psychiatric symptoms and cognitive performance, although these did not reach statistical significance at this early stage.
The really interesting part came next.
Additional funding allowed the researchers to offer all participants the opportunity to follow a ketogenic diet for a total of four months. Twenty-five participants completed this extension, with an average ketone level of approximately 1.26 mmol/L and 94% remaining in ketosis throughout.
After four months, there were significant improvements in positive symptoms, negative symptoms, depressive symptoms and cognitive performance, with all of these outcomes reaching P < .001.
Was it simply because people lost weight?
This is perhaps one of the most interesting findings from the study.
The researchers looked at whether the improvements in psychiatric symptoms could simply be explained by weight loss. They found that improvements in metabolic health, particularly glucose regulation and insulin resistance, were associated with improvements in psychiatric symptoms, whereas weight loss itself did not explain these changes.
There was also an association between the amount of time participants spent in ketosis and improvements in depressive symptoms. In other words, the findings raise the possibility that ketosis and improved metabolic function may be more relevant to the effects of the diet on the brain, rather than weight loss alone.
This fits well with what we already know about the relationship between metabolic dysfunction and serious mental illness. People with schizophrenia and bipolar disorder have higher rates of metabolic dysfunction, while some psychiatric medications can also contribute to weight gain, insulin resistance and other metabolic problems. You can learn more about this in my blog on brain energy, mitochondria and mental health. https://www.moiranewiss.co.uk/post/rewire-your-brain-energy-are-mitochondria-the-keys-to-mental-health-part-one
Why is this important?
This study adds to an increasingly interesting picture of mental health through a metabolic and bioenergetic lens.
The brain is an extremely energy-demanding organ, and ketone bodies provide an alternative fuel for the brain while also acting as signalling molecules. Ketones can influence much more than blood glucose and body weight, such as reducing inflammation and changing neurotransmitter signalling. Can you read more about this again in the blog mentioned above.
Of course, this was a relatively small study and it was not blinded, so we should be cautious about drawing firm conclusions. Larger and longer randomised controlled trials are needed to establish whether ketogenic diets can reliably improve psychosis and to understand which patients are most likely to benefit.
The results are certainly encouraging.
Further Investigation of Ketogenic Diets For Psychosis
And the research is already moving into an even earlier stage of illness. The University of Oxford has recently received £1.17 million in funding to investigate whether a ketogenic diet could benefit young people at clinical high risk of psychosis, potentially intervening before a first episode of psychosis develops. The trial will include 50 young people aged 14 to 35 randomised to either a 12-week modified ketogenic diet or a control diet. It will investigate psychiatric symptoms, cognition, sleep, physical health and markers of brain energy metabolism.
For me, this is another important step towards recognising that mental health and metabolic health cannot necessarily be separated. Rather than viewing the brain in isolation, we may need to consider how energy metabolism, insulin resistance, mitochondrial function and the availability of alternative fuels such as ketones influence brain function and mental health.
As the research base grows, it is becoming increasingly difficult to ignore the possibility that metabolic therapies could become an important part of the future of mental healthcare.
References
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
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