Twenty consecutive, chronic low back pain patients admitted to our pain treatment unit completed the Attributional Style Questionnaire (an instrument that detects a cognitive style that is correlated with, and that predicts, depression) and the Beck Depression Inventory. An age, sex, and education-matched group of normal subjects, a group of patients with asymptomatic essential hypertension, and a group of patients with end-stage renal disease receiving dialysis treatment served as controls. The majority of the chronic-pain and renal-dialysis patients had elevated depression scores, whereas none of the normal subjects or hypertensive patients were outside the nondepressed range. The Attributional Style scores of the pain and renal dialysis patients were significantly deviant from the normal control group, but no more so than those of the patients with hypertension. The results of this study suggest that individuals with a chronic medical condition, either symptomatic (chronic low back pain or renal disease) or asymptomatic (essential hypertension) in nature, develop an attributional style characteristic of depression. These data neither lend support nor refute the thesis that chronic pain syndromes are a variant of, or a masked, depression. Rather, this research implies that a more important question is what identifiable risk factors (for example, attributional style) predispose patients with chronic pain to develop a depressive illness.