Project Summary Substance misuse places a tremendous burden on individuals and society and remains high because so many youth initiate substance use at an early age and progress to dependence. In one of my NIDA sponsored R01s, I am funded to examine the effects of school and state-level penalties on youth substance use behaviors while accounting for anti-tobacco/drug media campaigns (R01 DA032843). My research signals a health issue of increasing importance that is youth exposure to the promotion of alcohol, tobacco, and other drug-related content via advertisements, online social networking, and other normalizing and pro-use messages. There is potential for leveraging social media as a tool to understand, inform, and potentially dissuade harmful substance use behaviors. However, a critical and necessary first step is to better understand displayed substance use references on key social media sites and how these displays are associated with use. In my second NIDA-sponsored R01, I am funded to investigate the implications of social media content and engagement for alcohol and marijuana use (R01 DA039456). I am a newly tenured investigator who has already made important contributions to the study of substance use policy and social media research. I will investigate social media posts for novel insight into drug use, especially newly emerging drugs that are increasing in popularity. I also aim to generate a strong scientific base about social media as a potential medium for delivering anti-/pro- substance use messages to young people. At this juncture, it is critical for me to receive support from this Independent Scientist Award so that I can devote all of my efforts towards continuing to build my research program and to enhance my scientific skills and advance me to the next level of achievement. I will collaborate with investigators at Washington University and nationally in order to gain further experience in sophisticated and efficient data mining analysis. I will additionally achieve an improved ability to synthesize results across multiple studies into strategic and actionable recommendations for tailored prevention messages to deliver on social media. This award will also enable me to devote a substantial amount of time to mentorship and the development of the next generation of researchers. In summary, this Independent Scientist Award will enable me to expand my knowledge base in targeted areas to significantly enhance my research trajectory in ways that would not be otherwise feasible.