Mood disorders: Edited by Cornelius Katona and Gregory E. SimonMajor depression and comorbid substance use disordersDavis, Loria,b; Uezato, Akihitob; Newell, Jason Ma,c; Frazier, ElizabethdAuthor Information aVA Medical Center, Research and Development, Tuscaloosa, USA bDepartment of Psychiatry and Behavioral Neurobiology, University of Alabama School of Medicine, Birmingham, USA cUniversity of Alabama, School of Social Work, Tuscaloosa, Alabama, USA dVA Medical Center, Mental Health Service, San Francisco, California, USA Correspondence to Lori Davis, MD, VA Medical Center (151), 3701 Loop Road East, Tuscaloosa, AL 35404, USA Tel: +1 205 554 2000; fax: +1 205 554 2877; e-mail: [email protected] Current Opinion in Psychiatry: January 2008 - Volume 21 - Issue 1 - p 14-18 doi: 10.1097/YCO.0b013e3282f32408 Buy Metrics Abstract Purpose of review The presentation of major depressive disorder is often complicated by the co-occurrence of substance use disorders, such as alcohol and illicit drug abuse or dependence. The article reviews the recent systematic research on the distinguishing baseline characteristics including demographic characteristics and the influence of family history, and clinical features such as depressive symptomatology and suicidal ideation, and the outcome of treatment for depression in patients with comorbid major depressive disorder and substance use disorders. The review also addresses the possible explanations cited in the literature as to why these two disorders tend to co-occur and the implications of the comorbidity of these illnesses on treatment. Recent findings Nearly one-third of patients with major depressive disorder also have substance use disorders, and the comorbidity yields higher risk of suicide and greater social and personal impairment as well as other psychiatric conditions. Although the treatment of comorbid major depressive disorder and substance use disorders with medication is likely effective, the differential treatment effects based on substance use disorder comorbidity have been understudied. Summary Emerging results of recent studies comparing the outcome of major depressive disorder patients with comorbid major depressive disorder and substance use disorders suggest that there are fewer differential effects based on comorbidity than previously anticipated by older assumptions from smaller, less methodologically rigorous studies. © 2008 Lippincott Williams & Wilkins, Inc.