Gluten Sensitivity, Celiac Disease, and Serious Mental Illness

Research suggests that immune reactions to gluten may be more common in certain psychiatric conditions, even when classic celiac disease is not diagnosed.

A large study published in Schizophrenia Bulletin (2011;37(1):94–100) examined antibodies associated with celiac disease and gluten sensitivity in 1,401 individuals with schizophrenia and 900 controls. Researchers measured antibodies to gliadin (AGA), tissue transglutaminase (tTG), and endomysium (EMA).

Key findings:

  • 23.1% of schizophrenia patients had moderate to high levels of IgA antigliadin antibodies, compared with 3.1% of controls

  • tTG antibodies were also more common in schizophrenia patients (5.4% vs 0.8%)

  • These differences persisted after adjusting for age, sex, and race

  • Antibody levels did not correlate with symptom severity (PANSS scores)

The authors concluded that people with schizophrenia have higher-than-expected immune markers related to celiac disease and gluten sensitivity, suggesting a possible immunologic subgroup.

A similar pattern has been observed in bipolar disorder. A study in Bipolar Disorders (2011;13(1):52–58) found that individuals with bipolar disorder had higher IgG antibodies to gliadin and deamidated gliadin compared with controls. However:

  • IgA antigliadin antibodies were not elevated

  • tTG antibodies (more specific for celiac disease) were not increased

This suggests that gluten sensitivity without classic celiac disease may be more common in bipolar disorder.

What this means clinically

  • These findings do not prove causation

  • They suggest immune reactivity to gluten may be relevant in some patients with schizophrenia or bipolar disorder

  • Certain individuals may benefit from further evaluation for celiac disease or non-celiac gluten sensitivity

As with many immune-brain connections, this appears to describe a subset of patients, not everyone with psychiatric illness.