Depression is common among opiate-dependent patients and has been associated with worse prognosis. This article reviews the literature on treatment of depressive disorders and symptoms among patients with opiate dependence. Depression bears a complex relationship to opiate dependence and may represent an independent disorder or may be engendered by psychosocial stress or toxic and withdrawal effects of drugs. Primary treatments for opiate dependence (e.g., methadone or buprenorphine maintenance or residential treatment) are associated with substantial improvements in depression. Studies of antidepressant medications have produced mixed results, some positive but more negative. It is not clear what accounts for these differences, and more research is needed to determine how to select opiate-dependent patients most likely to benefit from antidepressants. Fewer studies have examined psychosocial or behavioral interventions, but some of these also show promise. The data suggest a stepped model of care in which depression is evaluated and observed during the outset of treatment for opiate dependence and if it does not improve, specific psychosocial interventions or antidepressant medications tried. Research is needed on such integrated models of care and treatment algorithms to determine their efficacy and cost effectiveness.