To survey adults starting and currently on ketogenic diet therapy (KDT) for chronic epilepsy and determine whether there are beneficial effects on depression and anxiety. 

Ketogenic Diet Therapies are nonpharmacologic treatments shown to be effective in children and adults with intractable epilepsy.  Little is known about the effects of KDT on mood for adults with epilepsy.  An estimated 37% of people with epilepsy have psychiatric disturbances.  Although KDTs require certain diet restrictions, a low carbohydrate, high fat diet may improve negative affect in patients with or without existing comorbid psychiatric disorders. 

For adults already on a KDT for 3 months or more, a retrospective survey was administered assessing their mood prior to and while on a KDT.  Patients that were diet naïve completed a prospective pre-diet survey as well as one or more on-diet surveys after 3 months or more on-diet.  KDT responders were defined as experiencing ≥ 50% seizure reduction. 

Of 33 adults on KDT that completed the retrospective survey, 91% reported symptoms of anxiety(28) and/or depression(29) prior to starting.  Sixteen(48%) reported reduction in either anxiety(1), depressive symptoms(5), or both(10) on KDT.  Thirty-three percent had anxiety and/or depressive symptoms worsen.  Twenty-seven percent had all symptoms remain the same or solely anxiety symptoms remain the same.  In 3 patients who completed prospective surveys, 66% showed dramatically improved anxiety and depressive symptoms and all participants responded to KDT.  One participant without improvement reported increased anxiety.  

Chronic psychiatric symptoms may be under-reported in adults with epilepsy.  The majority of anxiety and depressive symptoms improved among nearly half of patients examined retrospectively and two thirds of patients examined prospectively.  Patients with worsening symptoms were symptomatic at baseline, indicating KDT likely did not result in development of psychiatric symptoms.  KDT may reduce psychiatric symptoms in adults with chronic epilepsy.