1. Introduction Results and Conclusions Comparisons of psychiatric hospitalization rates in the 12 months prior to and after baseline assessment revealed a significant treatment group by time interaction (X 2 = 7.23, p <.01). Exploration of this interaction effect indicated that the integrated treatment group (IT) demonstrated greater reduction in the incidence of any hospitalization, falling from 12.2% to 3.3%, while the parallel treatment (PT) group evidenced an increase from 6.5% to 10.8%. Examination of the total number of psychiatric hospitalization days in the 12 months pre- and post baseline also indicated a significant treatment group by time interaction (F(1,214) = 4.28, p <.04), with the IT group displaying a reduction in total days from 5.7 to 2.4 and the PT group an increase from 2.5 to 6.1 days. Similarly, a non-significant trend was found suggesting a decrease in the total number of hospital admissions for the IT group with a concurrent increase for the PT group (F(1,214) = 3.64, p <.06). Analyses of arrest rates 12 months pre- and post-baseline revealed a significant treatment group by time interaction (X 2 = 4.34, p <.04), consisting of a reduction in incidence of any arrest in the IT group from 11.4% to 7.3% relative to a marginal decrease in the PT group from 10.8% to 9.7%. No group differences were found in the frequency of arrests during these 12-month periods. In the area of employment, a treatment group by time interaction trend was found signifying a gain in employment for the IT group during the first year post-baseline, rising from 23% to 32% (X 2 = 3.02, p <.08). The PT group demonstrated a reduction in employment over this same time period, falling from 27% at baseline to 14% one year later. Measures of psychiatric status on the Brief Psychiatric Rating Scale (BPRS) did not change in the 12 months post-baseline and remained in the moderate severity range for both groups. Scores on the Substance Abuse Treatment Scale (SATS) were available for approximately half of each group providing a measure of treatment engagement. Analyses of SATS scores revealed an increase in the IT group, representing a shift from the early persuasion stage to the late persuasion stage, whereas the PT group scores remained in the early persuasion stage (F(1,100) = 4.98, p <.03). The results of this study provide evidence of enhanced effectiveness of integrated treatment for COPSD clients in the areas of reduced psychiatric hospitalization, decreased incidence of arrest, and increased engagement in the treatment process. Although there were no changes on measures of psychiatric severity, this may be representative of the chronicity of the severe and persistent mental disorders existing in this sample. Trends toward increased employment also suggest that the global effects of integrated treatment may manifest more fully over time in populations with chronic co-occurring psychiatric and substance abuse disorders. Acknowledgements Acknowledgements Comparative Analyses of Integrated Versus Parallel Treatment of Individuals with Co-Occurring Psychiatric and Substance Abuse Disorders Laurel Mangrum, Ph.D., Richard Spence, Ph.D. & Molly Lopez, Ph.D. University of Texas at Austin, Addiction Research Institute and the Texas Department of Mental Health and Mental Retardation Client Characteristics Client Characteristics Presented at the College on Problems of Drug Dependence, San Juan, Puerto Rico, June 16, 2004 Integrated TreatmentParallel Treatment Incidence of Any Arrest Average Number of Psychiatric Hospitalization Days Percentage of Clients Employed Average Substance Abuse Treatment Scale Scores Individuals with severe and persistent mental illness and substance abuse disorders present complex treatment needs that are often difficult to address in traditional mental health and substance abuse service systems. Research indicates that this population tends to over-utilize higher cost crisis-oriented services, such as psychiatric hospitalization, emergency medical care, and the criminal justice system, and to under-utilize more traditional and less costly treatment services, such as case management. Often, clients with these co-occurring disorders (COPSD) receive treatment from two different systems targeting either their psychiatric or substance abuse issues. This parallel treatment approach neglects the interactive nature of the COPSD client’s dual disorders and may lead to “revolving door” treatments between the mental health and substance abuse service systems. Recognition of this deficit in the behavior health field led to the development of integrated treatment programs that recognize the unique needs of the COPSD population by providing coordinated psychiatric and substance abuse interventions, as well as enhanced case management to obtain adjunct services addressing other social problems common in individuals with co-occurring disorders. The current study examines 1-year treatment outcomes of 216 individuals with co-occurring severe and persistent mental illness and substance abuse disorders who were randomly assigned to an integrated treatment program or to a control condition consisting of parallel delivery of psychiatric and substance abuse treatment. It was hypothesized that clients receiving integrated treatment would evidence increased engagement in treatment and greater positive outcomes relative to the control group. Incidence of Any Psychiatric Hospitalization Client Characteristics The authors acknowledge the Texas Dual Diagnosis Pilot research team comprised of representatives of the Texas Department of Mental Health and Mental Retardation (TDMHMR) and the Texas Commission on Alcohol and Drug Abuse (TCADA). The project was jointly funded by TDMHMR and TCADA. However, the findings and conclusions of this in this presentation are the opinions of the authors and do not necessarily reflect the official position of TDMHMR or TCADA. Client Outcomes Sample and Method The sample consisted of 216 eligible clients who were randomly assigned to either an integrated treatment program (N = 123) or to a parallel treatment control condition (N = 93). Analyses of demographic variables indicated that the two treatment groups were not significantly different on gender, age, race/ethnicity, or principal diagnoses. The groups were approximately 50% male, primarily White, and had a mean age of 36 years. The predominant diagnoses in both groups were major depression, schizophrenia, and bipolar disorder. The treatment groups were compared on outcome variables, including psychiatric hospitalization, arrest rates, employment status, psychiatric severity, and treatment engagement. Continuous outcome variables were analyzed using analysis of variance (ANOVA) with repeated-measures and between-groups factors. Weighted least squares methods for modeling categorical repeated-measures data with a between-groups design were used to examine categorical outcome variables.