Gender research in the National Institute on Drug Abuse National Treatment Clinical Trials Network: a summary of findings.

Background: The National Institute of Drug Abuse's National Drug Abuse Treatment Clinical Trials Network (CTN) was established to foster translation of research into practice in substance abuse treatment settings. The CTN provides a unique opportunity to examine in multi-site, translational clinical trials, the outcomes of treatment interventions targeting vulnerable subgroups of women; the comparative effectiveness of gender-specific protocols to reduce risk behaviors; and gender differences in clinical outcomes.

Objectives: To review gender-related findings from published CTN clinical trials and related studies from January 2000 to March 2010.

Methods: CTN studies were selected for review if they focused on treatment outcomes or services for special populations of women with substance use disorders (SUDs) including those with trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors; or implemented gender-specific protocols. The CTN has randomized 11,500 participants (41% women) across 200 clinics in 24 randomized controlled trials in community settings, of which 4 have been gender-specific.

Results: This article summarizes gender-related findings from CTN clinical trials and related studies, focusing on trauma histories, pregnancy, co-occurring eating and other psychiatric disorders, and HIV risk behaviors.

Conclusions: These published studies have expanded the evidence base regarding interventions for vulnerable groups of women with SUDs as well as gender-specific interventions to reduce HIV risk behaviors in substance-using men and women. The results also underscore the complexity of accounting for gender in the design of clinical trials and analysis of results.

Scientific Significance: To fully understand the relevance of gender-specific moderators and mediators of outcome, it is essential that future translational studies adopt more sophisticated approaches to understanding and measuring gender-relevant factors and plan sample sizes that are adequate to support more nuanced analytic methods.