Bullying, or peer victimization, is a particularly salient stressor that affects over 5 million adolescents in the US
every year, regardless of ethnicity, gender, or socioeconomic status. During adolescence, when concerns with
fitting in and gaining peer approval are heightened, experiences of peer abuse can elicit emotional distress and
fear of continued harassment. Indeed, work by MPI Schacter and others implicates peer victimization as a
unique prospective risk factor for anxiety during adolescence and indicates that chronic victims are two to three
times more likely to develop an anxiety disorder than their nonvictimized peers. Moreover, whereas overt (i.e.,
physical or verbal) victimization becomes less frequent as children get older, relational victimization (i.e.,
damage to social relationships) remains common and becomes increasingly emotionally taxing during
adolescence. Despite the strong and pervasive link between relational peer victimization and the development
of anxiety during adolescence, little is known about the underlying psychobiological mechanisms that account
for and maintain such associations. Given that stress-related biological alterations can predate mental health
problems and current treatments for anxiety are costly and intensive, it is crucial to identify malleable
therapeutic targets that can mitigate the emotional toll of peer trauma. The proposed R21 will evaluate threat
sensitivity as a potential target for the prevention and treatment of anxiety in peer victimized youth. The project
will be the first to examine the unique effects of peer victimization on physiological responses to threat during
adolescence and evaluate the prospective effect of aberrant threat sensitivity on adolescent anxiety. In
particular, we predict 1) compared to less victimized adolescents, more frequently victimized adolescents will
exhibit an exaggerated physiological response to potential threat during two validated tasks; 2) heightened
physiological threat responses will prospectively predict adolescent anxiety. MPI Marusak and co-I Jovanovic
have used these approaches in other pediatric populations in previous and ongoing studies, and have
demonstrated that threat biases (i.e., heightened arousal to potential threat) partially stem from childhood
adversities, such as being the target of familial abuse or neglect. However, the proposed study will be the first
to examine prospective associations among peer victimization, physiological markers of threat sensitivity, and
anxiety in adolescents. This novel line of work will directly inform future investigations examining threat
sensitivity as a mechanism and provide initial support for threat sensitivity as an important diagnostic tool to 1)
identify peer victimized youth who are at the greatest risk for developing anxiety and may benefit from cognitive
bias modification or other threat sensitivity reduction approaches, and 2) inform the design and modification of
developmentally sensitive cognitive behavioral intervention approaches. The proposed study provides a
foundation for future research incorporating a larger sample and neuroimaging measures to longitudinally
examine peer victimization as an impetus for neurobiological changes that increase anxiety risk.
