Substance use disorder treatment research in the National Drug Abuse Treatment Clinical Trials Network: Portfolio analysis of approved studies, 2000-2024.
Introduction: The National Drug Abuse Treatment Clinical Trials Network (CTN) is a program of clinical research funded by the National Institute on Drug Abuse that brings together academic scientists and community-based treatment providers to conduct research to improve care for substance use disorders (SUDs). This program-level analysis of the CTN portfolio’s scientific composition and scientific influence characterizes all CTN studies approved from 2000, the year that the first CTN study was approved for implementation, through 2024.
Methods: We integrated multiple administrative and scientific data sources to conduct a portfolio analysis of all CTN studies with funded and approved protocols through December 31, 2024. We used structured deductive content analysis to characterize scientific areas represented in the CTN portfolio, descriptive analyses to summarize portfolio growth, and bibliometric analyses to describe the scientific influence of CTN publications.
Results: Through the end of 2024, the CTN portfolio included 200 studies. CTN studies have predominantly focused on SUD treatment, particularly opioid use disorder, in specialized substance use treatment programs. The portfolio expanded over time to include a broader range of treatment settings, such as primary care; and research methods, including hybrid effectiveness-implementation designs and data science techniques. The CTN has supported the publication of 1296 peer-reviewed manuscripts, with the subset of primary outcome manuscripts demonstrating strong scientific influence relative to other publications supported by the National Institutes of Health.
Conclusions: Over 25 years, the CTN scientific portfolio has evolved to address changing priorities in SUD treatment research. This portfolio analysis provides a program-level characterization of the CTN and establishes a foundation for future metascience to further enhance its research and operations.