In both the United States (US) and China, substance use disorders (SUDs), particularly addiction to alcohol, tobacco and opiates, are significant public health problems despite substantial research resources devoted to understanding their causes, consequences and treatment. Two of the largest addictions research groups in each country are located at the University of Michigan [UM; which is one of the top institutions in the US in terms of total funding from National Institute on Drug Abuse (NIDA)] and Peking University [PKU; which houses the National Institute on Drug Dependence]. However, prior to the start of this project, information-sharing and research on addiction between these two institutions has been limited. This UM-PKU Discovery Award is designed to foster collaborations between addictions researchers at these two institutions with the goal of building the foundation for future research collaborations. Through regular ongoing team meetings via WeChat, travel by investigators in each direction for in-person meetings, and integration of early-career investigators in projects and meetings, this collaboration will evolve and expand during the funding period. In addition, this project will focus on addressing the topic of co-occurring pain and addiction. This project is important, because, despite research highlighting the unique importance of SUDs and pain by the proposed research team, few international collaborations exist between these researchers. Refining a novel behavioral treatment for co-occurring pain and addiction will make a significant impact because it could (1) decrease pain and substance use, (2) improve quality of life, and (3) decrease the costs to society of poorly managed pain and SUDs. This work will lay the groundwork for future funded joint research by UM and PKU faculty.