PROJECT SUMMARY/ABSTRACT Susan Yoon, PhD, MSW, is a social scientist whose overarching career goal is to prevent substance use and improve health outcomes among vulnerable, at-risk youth by identifying key mechanisms for risk and resilience to adolescent substance use following child maltreatment. This K01 Mentored Research Scientist Development Award will provide Dr. Yoon with rigorous training and systematic mentored research experiences that will accelerate her successful transition to an independent investigator in the field of adolescent substance use research. A team of highly qualified and committed mentors, who are prominent researchers in their respective fields, will guide and supervise her K01 research and training activities. The proposed career development plan encompasses four hands-on training goals to improve her knowledge and skills in: 1) adolescent substance use research with vulnerable youth; 2) the use of contextual/spatial (i.e., activity space) data; 3) the application of the resilience framework; and 4) advanced statistics, including person-centered analysis, multi-level modeling, and spatial analysis. During the K01 award period, Dr. Yoon will obtain and apply these new skills and knowledge to address important questions about the complex associations among child maltreatment, youth activity spaces—refers to areas or places a person visits in daily routine—and adolescent substance use. Child maltreatment and adolescent substance use are two serious, tightly connected public health concerns. Despite the well-established link between these phenomena, the underlying mechanisms and moderators (protective factors) of this link remains elusive, significantly hampering our ability to effectively prevent adolescent substance use. Thus, the proposed study aims to: 1) examine how distinct patterns of longitudinal maltreatment experiences are associated with different patterns of adolescent substance use trajectories; 2) investigate the mediating effects of risky attributes within youth's activity spaces on the association between child maltreatment and adolescent substance use; and 3) determine the extent to which protective attributes within youth's activity spaces buffers the impact of child maltreatment on substance use during adolescence. To address the study aims, Dr. Yoon will employ creative integration and analysis of diverse data sources, including data linkage between administrative child welfare records and geo-coded youth spatial exposure data. The study also introduces theoretical innovation through the integration of resilience theory and novel spatially-situated protective factors to understand resilience to substance use following child maltreatment. This study directly addresses NIDA's research priorities and strategic goals of supporting research to understand the complex interactions of environmental, behavioral, and social factors influencing drug use trajectories. Findings will offer valuable insight into key c...