This Stage II trial is responsive to the National Institute on Drug Abuse Program Announcement, Behavioral &Integrative Treatment Development Program (PA 07-111). Although many investigators have written about the need for single-gender treatment for women with substance use disorders (SUDs), there are very few specific therapies developed for this population, and even fewer empirical studies to determine the relative effectiveness of these therapies versus standard treatments in a mixed-gender setting. The primary aim of our current competing continuation proposal is to extend the work accomplished under the previous award (DA015434) by conducting at two sites a randomized controlled Stage II trial of the newly developed Women's Recovery Group (WRG) in a larger, more diverse sample of women than characterized that of our Stage I trial. We will randomly assign women with substance dependence to the twelve-session, single-gender, manual-based, women-focused Women's Recovery Group (WRG), or to an equivalent amount of the active comparison treatment, mixed-gender Group Drug Counseling (GDC), which focuses on recovery from SUDs without attention to women-specific antecedents to, and predictors of recovery from, SUDs. We will assess patients monthly and compare treatment outcomes at three months (i.e., end of treatment), six months (3-month post-treatment follow-up), and nine months (6-month post-treatment follow-up). We hypothesize that women randomized to the women focused, single-gender WRG will have better outcomes than will patients who receive mixed-gender GDC, as measured by (a) days of any substance use, (b) improvement in ASI drug and alcohol composite scores. In addition to testing the efficacy of the WRG, our second aim will be to investigate a priori hypotheses regarding potential moderators and mediators of treatment outcome. We will explore psychiatric severity and self efficacy as potential moderators of outcome as well as engagement in ancillary treatment and community support as potential mediators of treatment outcome. Finally, we will conduct exploratory analyses of group process characteristics of the WRG identified during the Stage I trial and explore differences in group process between single-gender WRG and mixed-gender GDC groups. PUBLIC HEALTH RELEVANCE: This study will further investigate the efficacy of a new manual-based, 12-session Women's Recovery Group (WRG) that combines an all-women group composition and women-focused content for women with substance use disorders, compared with a standard, effective mixed-gender group therapy condition. Even though nonstandardized women's substance abuse treatment groups are offered routinely in community-based substance abuse treatment programs, there are few previous empirical studies of the efficacy of such all-women's interventions and almost no randomized controlled trials of the effectiveness of all-women's treatment compared with delivering such treatment in a mixed-gender setting. The current study will enhance our knowledge of the efficacy of providing substance abuse treatment in a manual-based, all-women's recovery group compared with delivering such treatment in a standard mixed-gender format.