Social exclusion alters attention and autonomic regulation in adolescents with nonsuicidal self-injury.

Nonsuicidal self-injury (NSSI) poses a growing clinical challenge in adolescence, while imagery of NSSI is increasingly embedded in everyday digital life. Prior research indicates that adolescents who engage in nonsuicidal self-injury orient more rapidly toward NSSI-related imagery and report heightened urges to self-injure after viewing such content. What remains unknown is how social stress shapes these attentional biases. In the present study, we tested whether experimentally induced ostracism modifies attention to NSSI images, urges to self-injure, and autonomic regulation in adolescents with recent NSSI. Fifty adolescents who engaged in recent NSSI (M = 16.40 years, SD = 1.33) were randomized to inclusion vs. exclusion in an in-person ball-tossing ostracism paradigm and then completed free-viewing eye-tracking (with stimuli durations of 500/1000 ms) and dot-probe tasks (200/500 ms) that included NSSI images. NSSI urges, perceived stress, heart rate, and heart rate variability (Root Mean Square of Successive Differences, RMSSD) were assessed throughout the experiment. Social exclusion produced sustained reductions in RMSSD relative to inclusion, with no reliable heart rate differences. During free-viewing, both groups preferentially fixated NSSI images, but exclusion reduced the probability of first fixations on NSSI. In the dot-probe task, exclusion amplified the slowing from congruent to incongruent trials for NSSI. After viewing NSSI images, both groups showed increased urges and stress, with larger increases after exclusion. Acute interpersonal rejection reorganized attention, dampening initial gaze capture yet impairing later disengagement, occurring in the context of vagal withdrawal. These dynamics may help explain how social stress potentiates NSSI risk in everyday digital environments and highlight interpersonal context and post-rejection coping as modifiable targets for intervention. Trial Registration: German Clinical Trials Register Identifier: DRKS00025905.