The objective of this research was to evaluate the impact of Integrated Assertive Community Treatment (I-ACT) on psychiatric symptoms, drug use, housing status, and service utilization. A single-group repeated measures evaluation of outcome indicators at intake, 6 months, and 12 months examined changes over time with 555 respondents receiving outpatient treatment. While 555 received baseline interviews, figures vary on follow-up sample sizes and are listed as they are discussed in the paper. The study was implemented by a community treatment provider. The primary analyses used in this study were repeated measures ANOVA and the Friedman's two-way analysis test. Significant reductions in substance use (F(1.69, 553.02) = 94.30, p < .01) and psychiatric symptoms (F(1.98, 299.19) = 43.73, p = .0001) were found from baseline to 6 months and changes were sustained from the 6- to 12-month follow-up points. Similar results were found in housing status with the number of participants in stable housing rising significantly. Utilization of substance use and psychiatric treatment declined significantly across all three follow-up points, and physical health service use remained unchanged. I-ACT has demonstrated efficacy through controlled research studies, and this evaluation extends on these findings to demonstrate that I-ACT is effective in community service provision settings in reducing substance use and psychiatric symptoms. Further, the reduction in service use found across follow-up points indicates cost containment
