Arthritis is a leading cause of disability in older persons that reduces quality of life and restricts activity. Almost 80 percent of persons over age 70 have degenerative joint disease. Depression also is common in older persons, with a 16 percent prevalence in this group. Given the demonstrated association of depression with disability, treatment of depression may have an impact on arthritis-related pain and functional outcomes in primary care patients with comorbid arthritis and depression. Lin and colleagues report on the Improving Mood-Promoting Access to Collaborative Treatment (IMPACT) trial, the first randomized trial to study the effect of treatment of depression on arthritis-related disability.

The trial included primary care patients 60 years or older with major depression or dysthymia. The intervention included a collaborative care approach to depression, involving a nurse or psychologist, the primary care physician, and the patient. A prescription for antidepressant medication followed a stepped-care algorithm. A depression care manager delivered a six- to eight-session psychotherapy program and met weekly with a supervising psychiatrist and expert primary care physician to monitor patients’ clinical progress. Patients assigned to the usual-care group received routinely available depression treatment. Data were collected at baseline and at three, six, and 12 months. At these intervals, patients were assessed for level of arthritis pain, the degree to which that pain interfered with activities, general health, and overall quality of life. Functional status and depression also were assessed.

Of the 1,801 participants randomized to treatment or usual care, more than one half (1,001 patients) reported a diagnosis of arthritis or were being treated for arthritis at baseline. Approximately 57 percent were taking analgesic medication, 21 percent were taking opiates, and almost one half had taken antidepressant medications in the past three months. Depression treatment increased in both groups over the 12-month study period, with antidepressant use increasing from 43 to 66 percent in the intervention group and from 47 to 52 percent in the usual-care group. Psychotherapy increased from 8 to 47 percent in the intervention group and from 7 to 16 percent in the usual-care group.

Patients in the intervention group were more than twice as likely to experience a 50 percent reduction in depressive symptoms as measured by the Hopkins Symptom Checklist. Patients in the intervention group reported less interference in daily activities and less pain from arthritis than patients in the usual-care group. Improvements in mean Hopkins Symptom Checklist depression score were relatively synchronous with improvements in mean arthritis score over time, and a similar correlation was found for pain intensity and functional impairment from pain.

At the end of this 12-month study, patients who received enhanced depression-care management in the primary care setting showed lower arthritis-pain intensity and better functional outcomes, fewer depressive symptoms, and better general health status and overall quality of life than those who received usual care.

These findings lend further support to the notion that there is close interplay between depression and pain. The study found high comorbidity between arthritis and late-life depression. Because enhanced treatment of depression tends to reduce pain, recognition and treatment of depression could have broad public health implications, including a decrease in use of health care services.