A low-carb, high-fat ketogenic diet has positive effects on adults with epilepsy, according to a new study that determined ketosis can lessen symptoms of psychiatric disorders such as anxiety and depression and in turn decrease the frequency of epileptic seizures.

In a paper published Feb. 18 in Epilepsy & Behavior, researchers at Johns Hopkins Hospital explored the role of metabolism in psychiatric illnesses, a novel approach to understanding the gut-brain connection. They concluded that the longer patients followed a ketogenic diet, the fewer anxiety and depression symptoms they experienced. And when the patients showed less anxiety, their seizures happened less frequently.

Abigail Shegelman, a research program coordinator at The Johns Hopkins University School of Medicine and the lead author of the paper, told The Academic Times that this study is a first step to understanding how metabolism can affect psychiatric states and neurological diseases. In the paper, which also served as her master’s thesis, Shegelman found that ketosis may have independent effects on psychiatric symptoms in adults with epilepsy.

“This is a fascinating and relatively unexplored area of medicine which may have significant effects on different populations suffering from psychiatric illness,” Shegelman said.

Anxiety and depression are common among adults with epilepsy due to a variety of reasons, including restrictions on their ability to drive, the unpredictability of seizures and side effects of medications. Epilepsy is most often treated with antiseizure drugs, but 30% of patients with epilepsy experience drug inefficacy, according to the paper. 

In such cases, nonpharmacological treatments like ketogenic diet therapy are occasionally considered. Ketogenic diet therapies emphasize high-fat, low-carbohydrate foods, which induce fat metabolism and result in ketone body production, or ketosis. The patients in the current study followed the modified Atkins diet, which is similar to the traditional keto diet, though less restrictive. 

The study tested two types of adults with epilepsy — those who had already been following the modified Atkins diet for a length of time, and those who were new to it. The total sample included 100 patients of the Johns Hopkins Adult Epilepsy Diet Center who have intractable epilepsy, in which seizures cannot be controlled by medication.

Sixty participants who had been on the diet for at least one month were surveyed retrospectively, and their median time on diet therapy was two years. The median number of pre-diet seizures per week for this sample was one, and the median number of on-diet seizures per week was 0.1.

The participants who were new to the diet were given a baseline survey and an additional survey after three months or more on the modified Atkins diet. The median number of pre-diet seizures per week for this sample was one, and the median number of on-diet seizures per week was zero.

The full sample was tested with surveys that were adapted from the Patient Health Questionnaire-9, which measures for depressive symptoms and severity to diagnose depression, and the Generalized Anxiety Disorder-7, which does the same to diagnose anxiety. The researchers also used the Mood and Feelings Questionnaire, a commonly used psychological survey to measure depressive symptoms, to gauge how patients felt in the previous two weeks.

Of the patients who were tested retrospectively, 43% reported feeling that their mood improved with regard to depressive symptoms while on the modified Atkins diet. And 37% said they felt better on the diet in terms of anxiety symptoms. 

The longer the patients stayed on the diet, the lower their psychiatric scores were and the more their mood symptoms improved. Among the patients, more seizures per week on the diet correlated with worsening anxiety, while fewer seizures per week correlated with less anxiety.

“The correlations found in this study suggest potential positive effects of [ketogenic diet therapy] on mood, depression and anxiety in humans,” the authors said.

The patients who were new to the diet and tested prospectively did not see such strong results in their psychiatric symptoms, which could be due to their shorter time on the diet overall, according to the paper. They were only surveyed once while on the diet, and the authors said additional surveys at later time points while on the diet could have shown more dramatic changes in psychiatric and mood changes.

As an undergrad, Shegelman began working in the Adult Epilepsy Diet Clinic in the neurology department at Johns Hopkins Hospital. She noted that many of the clinic’s patients suffered from anxiety and depression and she found that the prevalence of psychiatric illness in adults with epilepsy was quite high, which led her to develop the study.

Future research should explore psychiatric disorders beyond depression and anxiety, the authors recommended, such as mood disorders, schizophrenia or attention deficit hyperactivity disorder. Bipolar disorder may also be an interesting avenue of study, as the medications prescribed for both bipolar disorder and epilepsy include a variety of mood-stabilizing drugs, the authors said.

“For future studies in epilepsy, this research connects neurology and psychiatry due to its unique cohort of patients and shows that with a larger data set and more participants, we may see even more significant results in how an epilepsy treatment may double as a psychiatric treatment as well,” Shegelman said. “This has far-reaching implications on psychiatric treatment, as well as management of psychiatric illness in epilepsy patients.”

The study, “The psychiatric effects of ketogenic diet therapy on adults with chronic epilepsy,” was published on Feb. 18 in the Epilepsy & Behavior journal. Abigail Shegelman, of Johns Hopkins University, was the lead author. Kathryn Carson, Tanya J.W. McDonald, Bobbie Henry-Barron, Luisa Diaz-Arias and Mackenzie Cervenka, all affiliated with Johns Hopkins University, served as co-authors.

At the time of the study, Shegelman was a student at The Johns Hopkins Bloomberg School of Public Health. Currently, she is a research program coordinator in the department of surgery at The Johns Hopkins University School of Medicine.