Testing an interpersonal risk pathway to suicidal ideation in adolescence: linking neural, psychological, and sociometric indices of socially relevant factors.

Sensitivity to the social environment is linked to suicidal ideation in adolescence, and little research has examined variance in neural functioning that may underlie this sensitivity and increase risk. Neural-based pathways to suicidal ideation are likely mediated by subjective experiences of the social environment. Loneliness is associated with both salience network connectivity and suicidal ideation. This longitudinal study tested whether greater salience network functional integration (i.e. global efficiency) in early adolescence, which may underlie hypervigilance to social experiences, predicts risk for future suicidal ideation via loneliness. Participants (N = 96; Mage=12.94) completed a fMRI scan to measure resting-state salience network functional integration. Loneliness, suicidal ideation, and a sociometric measure of adolescents' real-world peer environment were assessed over several years. Greater salience network global efficiency was associated with suicidal ideation two years later via higher levels of loneliness approximately one year later, particularly for girls. Across boys and girls, the effect of salience network global efficiency on loneliness appeared stronger for youth experiencing relatively larger decreases in peer acceptance over the prior year. While findings should be interpreted as preliminary given the sample size, they suggest a possible social-developmental pathway from early-adolescent salience network integration to future vulnerability for loneliness and suicidal thinking.