Several lines of evidence already point to a link between celiac disease and schizophrenia, leading scientists to wonder whether gluten somehow acts as an environmental trigger in people who have a genetic predisposition to schizophrenia. For example, children with untreated celiac disease have an increased risk of developing schizophrenia, and psychosis can be a symptom of celiac disease in adults.
In an article on the BBC website, Dr. Jun Wei, head of the team that received the funding grant, pointed out that nearly a third of people with schizophrenia have high levels of antibodies against wheat gluten in their body.
Furthermore, a variety of research studies have found that some patients with schizophrenia have a drastic reduction in their symptoms when they eliminate gluten from their diet. In some cases, their symptoms disappear entirely. Unfortunately, not all schizophrenia patients experience this beneficial effect. Scientists don't know why the gluten-free diet helps, and why it only helps some people and not others.
For a while now, Dr. Wei and the Genetics and Immunology Research Group at the UHI Millennium Institute have been looking for genetic links between schizophrenia and celiac disease. This month, they reported their discovery that the gene for tissue transglutaminase, which is involved in the production of gliadin antibodies when people with celiac disease eat gluten, may also have a role in the development of schizophrenia.
The same team has also found that the DQB1 gene (which is associated with celiac disease) may sometimes work together with the CLDN5 gene (which has a role in the immune function of the small intestine) to increase an individual's susceptibility to schizophrenia.
The grant money will be used not only to advance the group's research on gluten and schizophrenia but also to support its ongoing studies of possible links among gluten, schizophrenia, and diabetes.
Sources:
Bradford M et al. The TGM2 gene is associated with schizophrenia in a British population. American Journal of Medical Genetics Part B (Neuropsychiatric Genetics) 2009;150B(3):335-40.
Kalaydjian AE et al. The gluten connection: the association between schizophrenia and celiac disease. Acta Psychiatrica Scandinavica 2006;113(2):82-90.
Wei J, Hemmings GP. Gene, gut and schizophrenia: the meeting point for the gene-environment interaction in developing schizophrenia. Medical Hypotheses. 2005;64(3):547-52.
Read about other recent advances in celiac disease research.
