Differentiation of depression from chronic pain with the dexamethasone suppression test and DSM-III.

The concept of chronic pain has become enmeshed with depression. In an attempt to unravel this complex relationship, the authors studied a uniform group of 42 patients with chronic pain, i.e., patients who had chronic low back pain with defined organic pathology, in relation to the dexamethasone suppression test (DST). The results were analyzed in relation to the presence or absence of major depression and cortisol suppression. Forty-one percent of the patients with major depression had abnormal cortisol responses to dexamethasone administration; all patients without major depression had normal responses. These results suggest that chronic pain patients differ from patients with major depression and a positive DST.