Chipping Away at Schizophrenia

William Eaton  remembers that the letter came seemingly out of the blue. It was 1986, and Eaton—who now serves as chair of the Department of Mental Health—was known for his research on the epidemiology of schizophrenia. The letter was from Curtis Dohan, a Philadelphia internist who specialized in celiac disease, a rare autoimmune disorder that renders individuals intolerant to gluten, the proteins found in wheat and other cereals.

“Celiac disease is relatively straightforward to treat—you just remove all sources of gluten from the patient’s diet,” says Eaton, PhD. “What Dr. Dohan noticed was that among his patients who also had schizophrenia, the change in diet seemed to cure that, too.” Dohan’s letter wondered if there was some link between the diseases.

In February, Eaton and Danish collaborators published a paper in the British Medical Journal suggesting there is. Using the records of nearly 8,000 schizophrenic patients admitted to a Danish psychiatric facility between 1981 and 1998, the team showed that the risk of schizophrenia was three times greater for patients with a history of celiac disease. The research comes not from the 1986 letter, specifically, but from a broader inquiry into the link between autoimmune diseases, such as celiac disease, and schizophrenia. It has been known, for instance, that schizophrenia offers some protection against rheumatoid arthritis, another autoimmune disease.

Eaton’s discovery could help a small subset of schizophrenics who also test positive for celiac disease. In June, the researchers will apply for funds to start a double-blind trial to see if removing gluten from the diet of this group will control or eliminate the symptoms of schizophrenia. In more than three decades of research, Eaton has concluded that the battle against “the most important and damaging psychosis” will be won only gradually. The proposed trial “fits in with a general approach to schizophrenia that suggests the disease has many sources, and we’ll make progress by chipping away at them one at a time,” he says.

The link to celiac disease is a gratifying step in that direction, says Eaton, who regrets that he can’t tell Dohan of his discovery. Dohan died in 1992, and Eaton has lost touch with Dohan’s widow and grown children. “I’d like to tell them if I could,” he says. “I’d imagine they’d be thrilled.”