Junhan Cho, PhD, is the Co-Director of the Data Processing and Analysis Core at the USC Tobacco Center of Regulatory Science (USC-TCORS). His research focuses on employing advanced methodologies to explore complex patterns of youth behavioral changes using repeated measures in longitudinal data. Specifically, he investigates how diverse social contexts and psychological vulnerabilities intersect to influence substance use trajectories. His work includes conducting longitudinal and prevention studies on youth health risk behaviors, with particular attention to: 1) the developmental patterns of multiple, conjoint health risk behaviors; and 2) the longitudinal risk and protective pathways linking early contextual stressors to substance use across adolescence and young adulthood.