Depression and gastrointestinal illness: the joint use of biological and clinical criteria.

Occurrence and characteristics of depression were investigated in 37 consecutive patients suffering from gastrointestinal illness. More than 40% of patients with an organic digestive disease and about a quarter of those with functional gastroenterological complaints were found to suffer from a major depressive disorder according to DSM-III criteria. The dexamethasone suppression test--a laboratory marker of the endogenous depressive state--supported clinical diagnosis in several cases, yet its routine use to screen depression is not warranted because of its poor specificity. The results should alert the physician to include clinical and biological criteria for depression in the diagnostic work-up for gastrointestinal illness.