Grant: Operating Grant

Peer abuse among children and adolescents is a severe problem in many countries around the world. Canadian data show that 30% of boys and 24% of girls are being beaten up, threatened, taunted, or humiliated by their peers. Although physical peer abuse tends to decline over the course of primary school, nonphysical forms of abuse such as rumor spreading or social exclusion actually increase with age, with a sizable peak between ages 11 and 15 when children experience puberty and enter high school. Previous research shows that peer abuse in the early primary school years is an important environmental stressor that significantly impairs the mental and physical health of the victims. However, the neurophysiological pathway underlying the association between peer abuse and physical and mental health problems is still not well understood. Moreover, little is known about the effect of long-term exposure to peer abuse on youngsters' physical and mental health as they reach adolescence. Finally, from a disease prevention perspective, it is crucial to identify protective factors that can mitigate the negative health consequences of peer abuse. To address these issues, the proposed research aims to: 1) assess the effect of peer abuse on mental and physical health problems after the transition from primary school to high school 2) investigate the neurophysiological pathway through which peer abuse impacts on adolescent physical and mental health, specifically the mediating role of HPA axis activity (cortisol) in the stress-disease linkage, 3) examine the potential exacerbating effect of genetic vulnerability and of prior peer abuse experiences during elementary school on the link between peer abuse, HPA axis activity, and health problems, 4) test the potential mitigating effect of social support resources on the link between peer abuse, HPA axis activity, and health problems, and 5) explore potential gender differences in regard to the previously described linkages.