Chronic Physical Health Problems Moderate Changes in Depression and Substance Use Among Dual Diagnosed Individuals During and After Treatment

BACKGROUND: Physical illnesses frequently co-occur with depression and substance use disorders and may impact their improvement. Physical illness symptoms may overlap with or exacerbate somatic symptoms of depression. Individuals may use substances to cope with symptoms of physical illness. OBJECTIVES: We examined whether chronic physical health problems moderated changes in depression and substance use among dual diagnosed individuals during and in the year following treatment. METHODS: Participants were recruited from a Veterans Affairs dual diagnosis outpatient program between March 2000 and November 2007 and were randomized to either Integrated Cognitive-Behavioral Therapy or Twelve-Step Facilitation Therapy. A total of 214 veterans with assessment data for the variables of interest were included in analyses. Participants completed quarterly depression, substance use, and health assessments over an 18 month period. We used linear-mixed effects models to analyze patterns of change for depression and substance use. RESULTS: Individuals with severe chronic health problems and higher intake depression showed slower improvements in both nonsomatic and somatic depression symptoms. Individuals with severe chronic health problems and higher midtreatment substance use showed less improvement in substance use. CONCLUSIONS: Assessing and addressing physical health issues during depression and substance use disorder treatment may improve outcomes.