We investigate how stressful experiences and developmental processes across social, psychological, and biological domains shape adolescent mental health and life trajectories. Our research places particular emphasis on the emergence, persistence, and cessation of risk-taking behaviors, self-harm, and related social, emotional, and physiological processes. By identifying key risk and protective factors, we seek to advance early detection and prevention of self-harm as well as associated emotional and behavioral problems in adolescence, framed within a lifespan perspective.