Understanding suicide in sexual minority youth: neural reactivity to social cues as a moderating influence.

Sexual minority youth (SMY) experience heightened suicide risk, partly because of stigma surrounding sexual orientation identity. Neurobiological characteristics can influence reactivity to social cues (e.g., perceived liking or rejection) and suicide risk. These effects are exacerbated during adolescence-a developmental period of heightened sensitivity to social contexts. In this cross-sectional study of youth at varying psychiatric risk, we examined whether neural reactivity to social cues moderated the link between sexual minority status and suicidal ideation (SI) and whether sexual orientation victimization experiences further influenced these effects. Seventy-five youth (aged 14-22 years; 52% SMY, 48% heterosexual) reported depression, SI, and victimization, and completed a functional magnetic resonance imaging task involving viewing of unfamiliar face stimuli and receipt of social cues in rewarding and ambiguous contexts. Regions-of-interest analyses examined task-related neural reactivity in neural social regions. Moderation analyses were conducted using linear regressions. Sexual minority youth reported more severe depression, victimization, and SI (p < .05). Left temporoparietal junction (TPJ) activation to social cues, regardless of the degree of valence and certainty, moderated the link between sexual minority status and SI, where SMY (vs. non-SMY) with dampened left TPJ activity had higher SI. Exploratory analyses indicated that these associations were not further influenced by victimization. Results indicate enhanced suicide risk in SMY with altered social processing in the TPJ-a key region of neural social systems-across contexts, regardless of victimization history. Findings suggest that individual differences in neural reactivity to social cues are critical for understanding SMY suicide risk and have potentially important clinical implications.