A diet that’s touted for bipolar may trigger hypomania
STUDY: Palmer CM, Front. Nutr. 2026;13:1815787
STUDY TYPE: Case series
FUNDING: Independent
Background
The ketogenic diet is growing in popularity, as research funding has poured in from wealthy donors. The newly funded trials are still pending, but this paper gives a taste of the risk, authored by Chris Palmer, whose popular book on brain energy has raised interest in keto for mental health.
The Case Series
- 9 adults: 5 men, 4 women, average age 44
- 7 of the 9 participants had no prior bipolar-spectrum diagnosis (1 had bipolar II, 1 had schizoaffective); 3 had major depression; 2 had no psych history at all.
- Onset of hypomania or mania within 2 months (median 20 days, range 6-60) of starting ketogenic diet
- Ketosis confirmed through urine or blood testing, manic symptoms confirmed with YMRS
- Main symptoms: elevated mood, hyperactivity, decreased need for sleep (eg 2 hour/night). Duration: 67 days (range: 6 to 180 days).
- 6 out of 9 remained on the diet because of perceived mental or weight-loss benefits.
Earlier Hints
Though is the first report on keto-mania, there is a past report on the keto-esque Atkins diet.
The “ketogenic high” is another possible explanation. After several weeks of fasting, the brain switches its energy supply from glucose to ketones, and that can bring a state of heightened mental clarity, energy, and focus; intense spiritual feelings and even hallucinations.
Even brief fasting may alter mood. When 20 Muslim patients with bipolar fasted for Ramadan (from sunrise to sunset), 45% had a new mood episode, 71% of which were manic phase.
Practice Implications
- Though not addressed directly in the paper, this study raises doubts about ongoing efforts to treat bipolar disorder with the ketogenic diet.
- Dr. Palmer places it in the context of many other therapies for depression that can trigger mania: Antidepressants, and rarely ECT, light therapy, and antipsychotics.
- Learn about a diet for depression that is rated #1 for physical health and does not cause mania.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
What’s Your Take? Share in Comments
- Have you seen mental health benefits on the keto diet? Have you seen manic switches?
