A July 2018 article in Current Opinion in Psychiatry reviewed 26 articles about opioid use disorder treatment research written by 13 former NIDA International fellows from 9 countries. The article concludes (1) research conducted outside the United States can inform approaches to addressing the ongoing opioid crisis in the United States; (2) studies in countries with well-established health care systems have demonstrated the effectiveness of physician office-based opioid substitution therapies, which variously improved treatment uptake and outcomes while reducing barriers such as access to treatment, stigma, concurrent use of other substances, criminality, or incarceration rates; (3) studies in several countries demonstrated that changes in regulations and best practices related to naloxone have significant benefit in reducing opioid overdose deaths; and (4) research into implementation of evidence-based treatment in international settings with limited resources is applicable to U.S. regions that face similar geographical, fiscal, legal, and structural constraints. The authors also described the impact of the NIDA International Program on international drug abuse research collaboration. Since 1990, NIDA has supported research-training fellowships for nearly 500 postdoctoral researchers, mid-career professionals, and senior scientists from 110 countries. In 2016–2017, former NIDA fellows published 521 unique research articles indexed by PubMed. International Program Director Steven W. Gust, Ph.D., and IQ Solutions Consultant Judy McCormally, M.Sc., coauthored the review article, which is available in PubMed Central.