Depression associated with chronic pain: incidence, characteristics, and long-term outcome

Of 98 consecutive patients admitted to a pain management program for patients with nonmalignant chronic pain, 34 were definitely depressed, 20 were probably depressed, and 44 were not depressed by research diagnostic criteria (RDC). At the time of admission, no characteristic differences were observed among the three study groups except for, by definition, the presence of a RDC diagnosis of major depression (definite or probable) and an associated increase in Hamilton depression scale score and a group of MMPI scale scores. There was a 98% improvement rate for depression by participation of the patients in a nonpharmacologic program for nonmalignant chronic pain; there were no differences in frequency of depression among the three study groups at the time of dismissal. This progress was maintained at long-term follow-up (average, 11.6 months): 87 of 98 patients (88.8%) remained nondepressed.