Brain availability of monoamine precursors in adult coeliac disease.

Adults with untreated coeliac disease show signs of reduced central monoamine metabolism. The reason is obscure, and in the present study we investigated the brain availability of the monoamine precursors tryptophan and tyrosine in 11 untreated coeliac patients. The brain availability appeared to be unaffected in most of the patients, and the rise in serum tryptophan levels after oral casein administration was similar in coeliac and control subjects. Four of the 11 coeliac patients showed impaired brain availability with respect to tryptophan. Since they comprised all with a history of major psychiatric illness, this observation may have therapeutical implications for the management of depression in adult coeliac patients.