Abstract
The current review aims to synthesize the findings about the significance of psychiatric comorbidity for the outcome of maintenance treatment. A systematic literature search using electronic databases was conducted to search for relevant articles published up to November 2009. The reference lists of identified articles were inspected for further studies and citation searches were conducted. Comorbid psychiatric disorders often correlate with the course of opioid dependence and a variety of health-related and social problems. While early studies reported that severity of psychiatric symptoms were negatively related to the degree of improvement in patients with opioid dependence, more recent studies questioned this relationship. According to their findings, within-group changes in comorbid patients are comparable to those without psychiatric comorbidity, although comorbid patients seem to have special treatment needs. Thus it is concluded that maintenance treatments are effective also in patients with comorbid psychiatric disorders, but should be truly individualized, including additional psychopharmacological and psychotherapy treatments, to adequately treat these groups of patients.