Biopsychosocial risk pathways to school violence in youth: a scoping review of stress reactivity, mental health outcomes, and prevention.

School violence represents a major public health and educational concern with significant consequences for adolescents' psychological well-being, academic functioning, and social development. Increasing evidence indicates that violent behaviors in school environments arise from the complex interaction between individual vulnerabilities and broader social determinants. This scoping review aims to describe and discuss the available evidence on the risk factors, mental health outcomes, and prevention strategies associated with school violence. A comprehensive literature search was conducted across major databases, and studies were selected and charted according to predefined inclusion criteria. The evidence was analyzed following a developmental psychopathology framework. We identified and analyzed key individual risk factors, including emotional dysregulation, impulsivity, empathy deficits, trauma exposure, and psychiatric vulnerabilities such as attention-deficit/hyperactivity disorder, conduct disorder, and mood disorders. In addition, we mapped contextual determinants including family functioning, peer dynamics, school climate, and the growing role of digital environments, particularly cyberbullying. The review further categorized the psychological profiles of aggressors, victims, and bully-victims, highlighting the developmental fluidity of these roles. Attention was also given to biological and psychophysiological pathways linking school violence, trauma exposure, and adolescent mental health, including stress-system dysregulation, hypothalamic-pituitary-adrenal axis functioning, autonomic arousal, threat sensitivity, and neurodevelopmental vulnerability. Within a biopsychosocial framework, these mechanisms are discussed as potential mediators between adverse social experiences, emotional dysregulation, aggression, victimization, and subsequent internalizing or externalizing outcomes. We synthesized evidence on the mental health consequences associated with exposure to school violence, including depression, anxiety, post-traumatic stress symptoms, and suicidal ideation. Finally, evidence-based prevention and intervention strategies are discussed, emphasizing integrated approaches that combine school-based programs, family involvement, and collaboration with mental health services to support early identification and prevention. This review provides a biopsychosocial mapping of the current literature and highlights the need for future studies integrating psychosocial assessment with biological and psychophysiological measures of stress reactivity and neurodevelopmental vulnerability.