Sullivan M - Researchers sought to ascertain the relationship between depression and opioid use, abuse, and addiction via performing a review of prospective cohort, retrospective cohort, and other observational studies. Findings suggest that depressed patients have a slightly higher tendency for initiating opioid therapy than nondepressed patients but are at double risk for transitioning to long-term use. Patients with chronic pain and depression could use opioids to compensate for a reduced endogenous opioid response to stressors. Compared to nondepressed patients, depressed patients appear continuing opioid use at lower pain intensity levels and higher levels of physical function. Studies also suggested an increased risk of incident, recurrent, and treatment-resistant depression in relation to long-term opioid therapy. Depression also seems to increase the risk of abuse or nonmedical use of prescription opioids among adults and adolescents. Outcomes thus suggest understanding the close and multifaceted relationship of this therapy with depression is vital to understand long-term opioid therapy for chronic pain.