ORIGINAL ARTICLE Outcomes of a Residential and Community-Based Co-occurring Disorders Treatment Program Stephanie C. Acquilano 1 & Valerie A. Noel 2,3 & James Gamache 4 & Delia Cimpean Hendrick 5 & Robert E. Drake 6 # Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract We evaluated an intensive, integrated treatment program for men with serious mental illness and co-occurring substance use disorder, which incorporated several evidence-based interventions. Independent researchers rated transcripts from qual- ity improvement interviews to examine recovery in five key domains: housing, education/employment, family relationships, mental health, and substance use. The final sample comprised 82 participants; 60 (73.2%) had left the treatment pro- gram, and 22 (26.8%) remained engaged in services of varying intensity. Mean length of stay was 18.2 months (SD = 20.1). A large proportion of participants recovered on each domain (ranging from n = 40, 48.8% on education/employment to n = 55, 67.1% on substance use). Those who remained in treatment for at least a year (n = 37, 45.1%), compared with those who left earlier (n = 45, 54.9%), were significantly more likely to be in recovery in each of the five domains. Men with long-term dual disorders can achieve clinical and functional recovery when they receive intensive, integrated, evidence-based interventions for at least 1 year. Keywords Co-occurring disorders . Dual disorders . Dual diagnosis . Program evaluation . Evidence-based treatment . Integrated treatment . Recovery International Journal of Mental Health and Addiction https://doi.org/10.1007/s11469-020-00251-x * Stephanie C. Acquilano stephanie.acquilano@dartmouth.edu 1 The Dartmouth Institute for Health Policy & Clinical Practice, Geisel School of Medicine at Dartmouth, 1 Medical Center Drive, Williamson Building #501AD, Lebanon, NH 03756, USA 2 ACCESS Open Minds (Pan-Canadian Youth Mental Health Services Research Network), Montréal, Québec, Canada 3 Douglas Hospital Research Centre, Montréal, Québec, Canada 4 GateHouse Treatment, Nashua, NH, USA 5 WestBridge Inc., Manchester, NH, USA 6 Westat, Lebanon, NH, USA