This announcement encourages applications to conduct research on the effects of public policies on health-related behaviors and outcomes associated with alcohol, cannabis, tobacco, prescription drugs, and other substances. The purpose of the Notice is to advance understanding of how public policy may serve as a tool for improving public health and welfare through its effects on behaviors and outcomes pertaining to alcohol and other drugs. This Notice is intended to support innovative research to examine policy effects that have the potential to lead to meaningful changes in public health. Research projects that may be supported include, but are not necessarily limited to: causal analyses of the effects of one or multiple public policies; evaluations of the effectiveness of specific public policies as tools for improving public health through their effects on alcohol-, cannabis-, tobacco-, and other substance-related behaviors and outcomes; studies of disparities in policy effects and the role of policy in exacerbating or potentially reducing health disparities; and research to advance methods and measurement used in studying relationships between public policies and alcohol-, cannabis-, tobacco-, and other substance-related behaviors and outcomes.