People with a history of the digestive disorder celiac
disease are three times more likely to develop
schizophrenia than those without the disease, according to
a report by a researcher at the Johns Hopkins
Bloomberg School of Public
Health and colleagues in Denmark. The report is
published in the Feb. 21 edition of the British Medical
Celiac disease is an autoimmune disorder that impairs
the body's ability to digest the protein gluten, which is
found in grains and many other foods. The condition can
lead to diarrhea, weight loss and malnutrition. William W.
Eaton, lead author of the report and interim chair of the
Department of Mental Health at the School of Public Health,
said, "For years, scientists have suspected a link between
celiac disease and schizophrenia. Our research shows that
the link is moderately strong."
Eaton and his colleagues examined the records of 7,997
schizophrenic patients admitted to a Danish psychiatric
facility for the first time between 1981 and 1998. Those
records were compared to Denmark's national patient
register to determine if the schizophrenic patients or
their parents were previously treated for celiac disease.
The researchers also looked for diagnosis of similar
digestive disorders not previously associated with
schizophrenia, which included dermatitis herpetiformis,
Crohn's disease and ulcerative colitis.
The researchers found a small number of schizophrenic
patients were previously treated for celiac disease or had
a parent treated for celiac disease. Both conditions are
rare. The prevalence of celiac disease among schizophrenics
was 1.5 cases per 1,000 compared to 0.5 cases per 1,000 in
the larger control group. After adjusting for other factors
associated with schizophrenia, the researchers determined
that the risk of schizophrenia was three times greater with
a history of celiac disease. Crohn's disease and ulcerative
colitis were not associated with an increased risk of
"More research is needed to understand the link
between celiac disease and schizophrenia," Eaton said. "The
most important question is whether treatment for celiac
disease, in the form of a gluten-free diet, would benefit
the small proportion of individuals with schizophrenia who
are genetically prone to celiac disease but have not been
diagnosed with it."
The study was written by William W. Eaton, of Johns
Hopkins; Preben Bo Mortensen, Esben Agerbo and Majella
Byrne, of the National Centre for Register-Based Research,
Aarhus University, Denmark; and Ole Mors and Henrik Ewald.
Mortensen, of the Institute of Basic Psychiatric Research,
The research was funded by the Danish National
Research Foundation, Stanley Medical Research Institute and
the National Institute for Mental Health.