Does pain cause depression, or does depression cause pain? Many research studies have been conducted trying to establish and analyze the connection between pain and depression. A review of several of these studies, which was published in 2003, concluded (in part) that there was more pain found in those seeking help with depression and more depression in those seeking help with pain than when either condition was examined individually.
The two common medical conditions frequently occur together, respond to similar treatments, share the same brain chemistry pathways, and can become worse when not treated as co-existing diagnoses. In spite of this, underlying depression is seldom recognized by the physician or the patient when pain is the reason for the office visit. A work-up can include a complete history and physical exam, labs for various painful conditions, and x-rays; oftentimes, the patient is referred to a pain specialist or physical therapist. Approximately 50 percent of the time the work-up in a primary care setting does not include evaluation for depression.
Included in the 2003 review were 14 studies where the patient sought treatment for depression and then was assessed for pain; also included were 42 studies where the patient sought treatment for pain and then was assessed for depression. Excluded from the review were studies of patients whose pain had been diagnosed as a condition known to be painful (rheumatoid arthritis, fibromyalgia, diabetic nerve pain, etc.) Interestingly, there appears to be less depression in that population. The authors were more interested in chronic pain for which no concrete medical explanation could be found.