Neural reactivity to threat impacts the association between bullying victimization and suicide risk in youth.

Bullying victimization is a risk factor for suicidal ideation, suicide behaviors, and death by suicide in youth. However, not all victims of bullying report suicidal thoughts and behaviors, suggesting that there may be certain subgroups who are at high risk for suicide. Neuroimaging studies suggest that individual differences in neurobiological threat reactivity may contribute to increased vulnerability to suicide, particularly in the context of repeated exposure to bullying. The purpose of the present study was to examine the unique and interactive effects of past-year bullying victimization and neural reactivity to threat on suicide risk in youth. Ninety-one youth (ages 16-19) completed self-report measures of past-year bullying victimization and current suicide risk. Participants also completed a task designed to probe neural reactivity to threat. Specifically, participants passively viewed negative or neutral images during functional magnetic resonance imaging. Bilateral anterior insula (AIC) and amygdala (AMYG) reactivity to threat/negative images (>neutral images) was used to capture threat sensitivity. Greater bullying victimization was associated with increased suicide risk. There was also a bullying by AIC reactivity interaction such that among individuals with high AIC reactivity, greater bullying was associated with increased suicide risk. Among individuals with low AIC reactivity, there was no association between bullying and suicide risk. Results suggest that youth with increased AIC reactivity to threat may be particularly vulnerable to suicide in the context of bullying. These individuals may represent a high-risk group for subsequent suicide behavior and AIC function may be a promising objective prevention target.