Depression is a risk factor for noncompliance with medical treatment - Meta-analysis of the effects of anxiety and depression on patient adherence

Background: Depression and anxiety are common in medical patients and are a ssociated with diminished health status and increased health care utilizati on. This article presents a quantitative review and synthesis of studies co rrelating medical patients' treatment noncompliance with their anxiety and depression. Methods: Research on patient adherence catalogued on MEDLINE and PsychLit f rom January 1, 1968, through March 31, 1998, was examined, and studies were included in this review if they measured patient compliance and depression or anxiety (with n>10); involved a medical regimen recommended by a nonpsy chiatrist physician to a patient not being treated for anxiety, depression, or a psychiatric illness; and measured the relationship between patient co mpliance and patient anxiety and/or depression (or provided data to calcula te it). Results: Twelve articles about depression and 13 about anxiety met the incl usion criteria. The associa- tions between anxiety and noncompliance were v ariable, and their averages were small and nonsignificant. The relationship between depression and noncompliance, however, was substantial and signifi cant, with an odds ratio of 3.03 (95% confidence interval, 1.96-4.89). Conclusions: Compared with nondepressed patients, the odds are 3 times grea ter that depressed patients will be noncompliant with medical treatment rec ommendations. Recommendations for future research include attention to caus al inferences and exploration of mechanisms to explain the effects. Evidenc e of strong covariation of depression and medical noncompliance suggests th e importance of recognizing depression as a risk factor for poor outcomes a mong patients who might not be adhering to medical advice.