Effectiveness of treatment for substance abuse and dependence for dual diagnosis patients: A model of treatment factors associated with one-year outcomes

Objective: This study examines a model of treatment for substance abuse and dependence for patients with substance use disorders and concomitant psych iatric disorders. The model focuses on five interrelated sets of variables (social background, intake functioning, dual diagnosis treatment orientatio n, patients' change on proximal outcomes, and aftercare participation) that are hypothesized to affect dual diagnosis patients' 1-year posttreatment o utcomes. Method: A total of 981 male dual diagnosis patients completed asse ssment at intake, discharge and 1-year follow-up. The relative importance o f each set of variables as predictors of outcome was estimated by construct ing block variables and conducting path analyses. Results: Dual diagnosis p atients had a higher abstinence rate at follow-up (39%) than at intake (2%) ; they also improved on freedom from psychiatric symptoms (from 60% to 68%) and employment (from 20% to 29%). At follow-up, patients in programs with a stronger dual diagnosis treatment orientation showed a higher rate of fre edom from psychiatric symptoms (71%) than did patients in weaker dual diagn osis treatment oriented programs (65%); they also were more likely to be em ployed (34% vs 25%). More change on proximal outcomes and more aftercare pa rticipation were also associated with better I-year outcomes. Patients with less severe psychiatric disorders improved more and responded better to du al diagnosis oriented treatments than did patients: with more severe psychi atric disorders. Conclusion: Treatment programs for substance use disorders that adhere to principles of dual diagnosis treatment obtain better outcom es for dual diagnosis patients, especially for patients with less severe ps ychiatric disorders.