Peer victimization predicts heightened inflammatory reactivity to social stress in cognitively vulnerable adolescents.

BACKGROUND During adolescence, peer victimization is a potent type of social stressor that can confer enduring risk for poor mental and physical health. Given recent research implicating inflammation in promoting a variety of serious mental and physical health problems, this study examined the role that peer victimization and cognitive vulnerability (i.e. negative cognitive styles and hopelessness) play in shaping adolescents' pro-inflammatory cytokine responses to an acute social stressor. METHODS Adolescent girls at risk for psychopathology (n = 157; Mage  = 14.73 years; SD = 1.38) were exposed to a laboratory-based social stressor before and after which we assessed salivary levels of three key pro-inflammatory cytokines - interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). RESULTS As hypothesized, adolescents with greater peer victimization exposure exhibited greater increases in IL-6 and IL1-β in response to the laboratory-based social stressor. Moreover, for all three cytokines individually, as well as for a combined latent factor of inflammation, peer victimization predicted enhanced inflammatory responding most strongly for adolescents with high levels of hopelessness. CONCLUSIONS The findings reveal a biological pathway by which peer victimization may interact with cognitive vulnerability to influence health in adolescence.