Twenty-five years of the NIDA clinical trials network and the future of addiction research.

The National Institute on Drug Abuse Clinical Trials Network (CTN) was established in 1999 to bridge the persistent divide between addiction research and clinical practice through partnerships between researchers and community treatment providers. This editorial examines the evolution of the CTN over its first 25 years and considers priorities for its future. Drawing on the historical development of the Network and articles in this 25-year special collection, we examine changes in the populations and settings represented in CTN research, the incorporation of implementation science, the evolution of community partnerships, the scientific value of accumulated CTN data and experience, and emerging clinical and methodological priorities. Over 25 years, the CTN has developed from a network focused principally on clinically relevant effectiveness trials into a broader national infrastructure for clinical trials and translational addiction research. Its research has expanded beyond specialty addiction treatment programs into primary care, emergency departments, hospitals, community health centers, pharmacies, and other settings in which people with substance use disorders receive care. The Network has also increasingly addressed populations historically underrepresented in addiction research, incorporated implementation questions into clinical research, strengthened community engagement, and used accumulated trial data and emerging analytic methods to generate new scientific knowledge. These developments demonstrate that the value of a clinical research network extends beyond individual trial outcomes. Clinical trials should remain at the core of the CTN’s scientific mission. However, trial designs and complementary research methods should be determined by the scientific questions being addressed. The CTN’s future impact will depend on its ability to conduct rigorous multisite trials while incorporating implementation, representation, community partnership, and accumulated data and responding rapidly to changes in the drug supply and addiction care environment. These capabilities can help the Network generate evidence that is rigorous, relevant, timely, and more likely to improve addiction care.