Theoretical issues -- Epidemiological perspectives on co-occuring anxiety disorder and substance use disorder -- The neurobiology of anxiety: potential for co-morbidity of anxiety and substance use disorders -- Research findings -- Posttraumatic stress disorder and substance use disorder: neuroimaging, neuroendocrine, and psychophysiological findings -- Co-morbidity of social phobia and alcohol use disorders: a review of psychopathology research findings -- Panic spectrum disorders and substance use -- Treatment strategies -- Treatment of co-morbid obsessive-compulsive disorder and substance use disorders -- Treatment for co-morbid posttraumatic stress disorder and substance use disorders -- Treatment of co-occuring alcoholism and social anxiety disorder -- Treating co-morbid panic disorder and substance use disorder -- Cognitive- behavioral treatment of co-morbid panic psychopathology and tobacco use and dependence -- Personality-based approaches to treatment of co-morbid anxiety and substance use disorder -- Medical management of co-morbid anxiety and substance use disorder -- Integration and conclusions -- Anxiety disorder and substance use disorder co-morbidity: common themes and future directions.