CHRONIC PAIN-ASSOCIATED DEPRESSION - ANTECEDENT OR CONSEQUENCE OF CHRONIC PAIN - A REVIEW

Objective: To determine the current status for the association of chro nic pain and depression and to review the evidence for whether depress ion is an antecedent or consequence of chronic pain (CP). Design: A co mputer and manual literature review yielded 191 studies that related t o the pain-depression association. These reports were reviewed and sor ted into seven categories relating to the topic of this paper. Eighty- three studies were then selected according to inclusion criteria and s ubjected to a structured review. Setting: Any medical treatment settin g including pain treatment as inclusion criteria for selection of stud ies. Patients: Any patients with any type of chronic pain. Results: Th e reviewed studies were consistent in indicating that there is a stati stical relationship between chronic pain and depression. For the relat ionship between pain and depression, there was greater support for the consequence and scar hypotheses than the antecedent hypothesis. Concl usions: Depression is more common in chronic pain patients (CPPs) than in healthy controls as a consequence of the presence of CP. At pain o nset, predisposition to depression (the scar hypothesis) may increase the likelihood for the development of depression in some CPPs. Because of difficulties in measuring depression in the presence of CP, the re viewed studies should be interpreted with caution.