Chris Palmer, MD was a co-author of this 
Chris Palmer, MD was a co-author of this 2018 case study which showed an improvement in schizophrenic symptoms in young Ecuadorian twins on a ketogenic diet. They were a male and a female, diagnosed with schizophrenia at the ages of 14 and 18. At the time of the study they were 22 years old.
What can we learn from this study?
A central focus of this study was to assess how the ketogenic diet would affect these patients’ schizophrenic symptoms.
This pilot study employed a 6 week intervention of the ketogenic diet for these two people with schizophrenia. (A pilot study is a small study used to test whether the study question warrants a full-scale investigation. It is a building block for future medical research.) After allowing them to adapt to ketosis for 15 days, the twins’ psychiatric symptoms were evaluated. This evaluation was conducted by a psychiatrist who was unaware of the dietary intervention.
How did 15 days on the ketogenic diet affect the twins’ symptoms?
First off, they both lost weight. An effect well known for the ketogenic diet.
A second, and more important outcome was an improvement in their schizophrenic symptoms.
How were their schizophrenic symptoms measured?
The measure used in this study was the Positive and Negative Syndrome Scale (PANSS). The PANSS is an assessment used to evaluate the positive and negative symptoms of schizophrenia. It is often used in patient care in psychiatry. It is also used in studies done to evaluate the efficacy of new medications. Therefore, it was an appropriate tool to use to evaluate this dietary psychiatric intervention.
Positive and negative symptoms of schizophrenia?
Yes, schizophrenia has symptoms which are both positive and negative.
Positive symptoms are the presence of abnormal characteristics. One group of positive symptoms is hallucinations (false sensory experiences that feel real). Delusions (false beliefs that persist despite a contradicting reality) are another set of positive symptoms. Negative symptoms are the absence of characteristics that would be present in a typical person. These include a lack of motivation, diminished thought content, lack of social interaction, diminished emotional responsiveness and expression, and loss of pleasure. Together the positive and negative symptoms form the bulk of some of the basic dysfunctions in schizophrenia.
The case study results
It is important that a tool that can measure both positive and negative symptoms was used in this study. Despite not being able to maintain high levels of ketosis for long periods of the experiment, the PANSS scores improved for both twins, that is, their schizophrenic symptoms got better. This improvement lasted only as long as the patients stayed on the diet. At the end of the study the participants went back to their normal diet and their symptoms returned. The exacerbation of symptoms while off the diet is a further vote of confidence that it was the diet that spurred the improvement.
What does this case study mean about keto and schizophrenia?
Because this was a small, pilot study, it does not demonstrate anything conclusively. It does provide another bit of evidence to support the idea that more research is called for to explore the efficacy of the ketogenic diet for the treatment of schizophrenic symptoms.
Another case study about the efficacy of the ketogenic diet might also be of interest to you, see Dr. Palmer’s case study. The ketogenic diet and remission of psychotic symptoms in schizophrenia: Two case studies.
See the Ecuadorian twin study for yourself.