Find a therapist to treat psychosis

Case studies are limited in what they can tell us about dietary interventions for severe mental illness (SMI).

Ketogenic diets may be helpful to some people with schizophrenia.

Carefully conducted studies of ketogenic diets for people with SMI remain lacking.

While travelling on a series of national speaking engagements for the “Take Back Your Health Tour,” Health and Human Services Secretary Robert F. Kennedy, Jr. recently made a remarkable claim. At the Tennessee State Capitol, Kennedy stated that a doctor at Harvard had “…cured schizophrenia using keto diets….” and that “there are studies right now that I saw two days ago where people lose their bipolar diagnosis by changing their diet.”

As a professor of psychology, neuroscience and behavior who has worked in the field of severe mental illness for 25 years, I know that “curing” these chronic conditions is not that simple.

The Challenges Posed by Severe Mental Illnesses

Schizophrenia can be a cruel and chronic illness that is estimated to affect 3.7 million Americans, and 5.7 to 7 million suffer from bipolar illness. Many of these members of our community populate our homeless shelters, public parks, emergency rooms, and increasingly, our prisons. Schizophrenia is routinely listed among the top 15 causes of disability worldwide, with rates of unemployment for those diagnosed far above national norms in the United States. The life expectancy of someone with schizophrenia is 15-25 years shorter than the U.S. average. Perhaps most tragically, nearly 5% of people with schizophrenia die by suicide. Similarly, for those with bipolar illness, unemployment and mortality rates are elevated, too (the news of the suicide of actor David Carradine makes this clear).

Issues Posed by Severe Mental Illness Transcend Politics

Even in a deeply polarized political environment, we can all agree that schizophrenia and bipolar illness represent major threats to our public health and cause untold misery for millions of Americans and their loved ones. These realities make Secretary Kennedy’s comments particularly problematic. First, the science he cites simply doesn’t add up. In his comments on schizophrenia, Kennedy appears to be referring to case studies described by Dr. Chris Palmer, an assistant professor of psychiatry at Harvard Medical School. Palmer is director of the Metabolic and Mental Health Program at McLean Hospital. In one of Palmer’s case studies—a male patient with a nearly 15-year history of schizophrenia suffering from hallucinated voices, irrational beliefs, and other disabling symptoms—went on a high-saturated-fat ketogenic diet that produced a loss of 10 lbs. in three weeks. Along with the weight loss there was, Palmer claimed, “...a dramatic reduction in his auditory hallucinations and delusions, and improvement in his mood, energy, and ability to concentrate.”

The Limits of Individual Cases

Palmer based his conclusions on the use of a single-subject research design. In these studies, conclusions regarding the effectiveness of a new treatment are drawn by measuring a disease target of interest (say, frequency of voice hearing) at the start of the study, administering the new treatment (in this case a ketogenic diet consisting of high intake of saturated fat and low intake of carbohydrates ), assessing the effect of that treatment (in this case, reducing voice hearing), and then withdrawing that treatment to see if voice hearing returns to pre-diet levels.

The problem is the actual design of Palmer’s research did not include a key component: withdrawal of the treatment. Instead, the patient lapsed on their diet five times of their own accord during the year in which the patient was studied, and during each of those five times the patient’s symptoms increased. Palmer assumed that increased symptoms were caused by the disruption of the ketogenic diet but these results could just as easily be attributed to worsening symptoms associated with the natural course of the illness. Schizophrenia is notorious for its oscillations in symptoms over time, with sustained periods of stability alternating with episodes of acute symptoms.

Regardless of the specifics of each of Palmer’s cases, these reports are simply that — individual case studies. Without groups of people with schizophrenia-spectrum illness, rigorously diagnosed and randomly assigned to diet and non-diet control groups, with careful monitoring of dietary change, and reliable measurement of outcomes, these case studies remain only suggestive, and far from conclusive. (To Palmer’s credit, in a variety of public comments he has distanced himself from the use of ketogenic diets as “cures” for schizophrenia).

This is not to say that changes in diet for specific people with severe mental illness can’t be helpful in their healing journey. But to generalize from case studies to prescription creates an expectation of a simple, quick cure that is unwarranted based on years of study of these complex disorders.

What is most concerning is that Kennedy’s comments can be seen as contributing to a narrative of stigma that suggests that those suffering with mental illnesses could be cured if they simply paid more attention to their diets, or if they simply made more positive health choices. How wonderful it would be if we lived in a world in which simple, overlooked interventions could solve the most severe problems in thinking, feeling, and living that have plagued and baffled humanity since at least the time of antiquity. But things are not that simple.

Find a therapist to treat psychosis

To his credit, the Secretary has for much of his career combatted the influence of Big Pharma in the practice of health care. In this regard, the MAHA movement he leads could provide a direction forward. There are numerous non-pharmacological interventions, including training in social and cognitive skills, and integration of community-based primary and mental health care that have a strong or growing research base. Yet some studies show that fewer than 10% of patients are enrolled in these treatments at any one time. A stronger focus on mental health care accessibility could help us get closer to the “cure” that Kennedy and so many Americans seek for these debilitating illnesses.

Palmer, C.M. (2017). Ketogenic diet in the treatment of schizoaffective disorder: Two case studies. Schizophr Res, 189, 208-209.

There was a problem adding your email address. Please try again.

By submitting your information you agree to the Psychology Today Terms & Conditions and Privacy Policy

© Psychology Today