Gluten and Schizophrenia Connection

Psychiatrists have speculated about a potential link between gluten and schizophrenia for more than three decades. In fact, the term "bread madness" was coined half-a-century ago to describe schizophrenia—there were reports of mental patients recovering spontaneously when bread products (that being, the bulk of gluten-containing foods in their diets) weren't available.

Although there have been some case reports of patients with schizophrenia improving with a gluten-free diet, even researchers in the field speculate that only a very small percentage of schizophrenics may ultimately benefit from dietary interventions such as a gluten-free diet.

It's also important to recognize that there are no currently accepted dietary recommendations regarding gluten and schizophrenia. Still, researchers are beginning to look at the complex connections that may exist in the immunology of celiac disease, gluten sensitivity, and schizophrenia.

Schizophrenia Is a Severe Mental Disorder

Schizophrenia is a chronic, severe and potentially disabling brain disorder. It affects about 1% of the overall population. People with schizophrenia suffer from a variety of different symptoms, but may hear voices (hallucinations) or have fixed, false beliefs (delusions) such as believing that people are plotting against them.

To control schizophrenia, physicians generally prescribe antipsychotic medication. Support from a psychiatric team is often an essential component of care.

Although in some people the disease can be controlled enough for them to be productive members of society, others with schizophrenia are significantly disabled. Although most people with schizophrenia aren't violent toward others, approximately 10% ultimately commit suicide.

Wheat Gluten as a Possible Schizophrenia Factor

Back in 1976, researchers published a study in Science speculating that the gluten protein in wheat caused or promoted schizophrenia. "Schizophrenics maintained on a cereal grain-free and milk-free diet and receiving optimal treatment with neuroleptics [i.e., antipsychotic drugs] showed an interruption or reversal of their therapeutic progress during a period of 'blind' wheat gluten challenge," the scientists wrote. "After termination of the gluten challenge, the course of improvement was reinstated. The observed effects seemed to be due to a primary schizophrenia-promoting effect of wheat gluten."

As the years passed, more studies chimed in on the potential effects of gluten in schizophrenia, with mixed results. A study published in 1981 kept eight chronic schizophrenia patients on a gluten-free, milk-free diet and then challenged them with wheat gluten for five weeks. The study found no difference in their schizophrenia symptoms when they were consuming gluten.

More recent research has noted this effect of the gluten-free diet in a small subset of patients with schizophrenia and has recommended large-scale epidemiological studies and clinical trials to determine why this happens and which schizophrenia patients might benefit.

Gluten Antibodies Involved

People who have untreated celiac disease (those who are eating a conventional diet with gluten-containing foods) show high levels of specific antibodies, including the tTG-IgA and EMA-IgA antibodies, when celiac blood tests are performed. These tests are specific to the intestinal damage found due to gluten in celiac disease.

Some people with schizophrenia, meanwhile, show high levels of other antibodies to gluten—notably the AGA-IgG and the AGA-IgA antibodies. For example, one study that looked at 1,401 schizophrenia patients found 23% of them had moderate to high levels of AGA-IgA.

The AGA-IgA and AGA-IgG antibodies are considered less specific to celiac disease—they indicate an immune system reaction to gluten is going on, but not the specific villous atrophy found in celiac disease.

A comprehensive 2014 review of the relationships sums up by asserting that celiac patients for years have been perceived to be at increased risk of schizophrenia and that indeed entire population studies (the Danish National Register in the late 1980s and 1990s) support the association that celiac disease occurred before the onset of schizophrenia.

At the same time, research studying the effect of eliminating gluten from the diets of schizophrenic patients showed that psychotic symptoms did not decline in all patients.

More recently, in a study that looked at people with celiac disease and people with schizophrenia separately, the two groups seemed to be reacting to different parts of the gluten protein, establishing that any immune response to gluten in schizophrenia is different from that of celiac disease, and is independent of any potential intestinal damage.

A Word From Verywell

Although it's not generally accepted in the mental health field, some researchers, including director of the Center for Celiac Research and Treatment at MassGeneral Hospital for Children Dr. Alessio Fasano, believe that an as-yet undefined subset of people with certain mental disorders, including schizophrenia and also autism, seem to improve or even recover on a gluten-free diet, even if they don't have celiac disease.

Researchers currently are working to identify a specific biomarker that could lead to a medical test that will identify most or all people with gluten sensitivity, including those with schizophrenia. Until more research has been done, medical professionals don't recommend going gluten-free in an effort to help schizophrenia.