Ketogenic Diet for Psychotic Disorders: A Randomised Controlled Pilot Study in Psychotic Inpatients (PSYDIET)

WHY IS THIS IMPORTANT?
Ketogenic diet (KD) is a low-carbohydrate, high-fat diet restricting glucose and forcing metabolism of ketones as energy substrates for the brain. Although KD is effective for treatment-resistant epilepsy, we have very limited evidence on the effects on other disorders, such as psychotic disorders, which are associated with an impaired brain energy metabolism. Some anecdotal and case studies have suggested some benefits, however, no previous randomised controlled studies have been published. Therefore, we aim to conduct the first randomised controlled pilot study and 1) investigate the feasibility of modified KD (MKD) intervention in an inpatient setting, and 2) to examine the efficacy of MKD in alleviating psychotic symptoms as an adjunctive treatment.

HOW ARE WE DOING THIS STUDY?
The study is a 6-week randomised MKD pilot study in psychotic inpatients (intervention group n=40; control group n=20) and it will be conducted at Kuopio University Hospital, Finland. In the MKD group, carbohydrate consumption is limited to 15-20 g/day to induce ketosis, while control participants will have their normal hospital meals. A percentage of participants adhering to the MKD and reaching ketosis, MKD-related experiences and adverse effects and changes in psychotic symptoms will be assessed.

WHAT ARE WE HOPING TO FIND?
We hypothesise that adherence to the restrictive MKD will be challenging in psychotic inpatients but will be achievable in an inpatient setting with support from hospital/research staff. We further hypothesise that the MKD intervention may result in some benefits in psychotic symptoms, however, also several adverse effects will be reported. The results of this pilot study will be valuable for informing larger future intervention studies.