Recent Non‐Suicidal Self‐Injury in Autistic Adolescents and Adults: Characteristics, Clinical Correlates and Suicidal Thoughts and Behaviors

Non-suicidal self-injury (NSSI) is prevalent among autistic adolescents and adults, yet research on its clinical characteristics, functions, and association with suicidal thoughts and behaviors (STBs) in this population remains limited. This study compared these domains between autistic adolescents and adults with and without recent NSSI. 520 autistic adolescents and adults (260 with recent (past 6 months) NSSI; 260 age- and sex-matched without recent NSSI group) completed measures of NSSI characteristics and functions, STBs, mental health, and autistic traits. Group comparisons were conducted with Benjamini-Hochberg correction for multiple comparisons. The recent-NSSI group demonstrated poorer psychological quality of life, lower self-compassion, greater depression and anxiety, elevated autistic traits, and greater alexithymia and camouflaging than the no-recent-NSSI group. Lifetime passive suicidal thoughts, active suicidal thoughts, and suicide attempts were over four, five, and three times more likely in the recent-NSSI group, respectively. All 36 participants who reported a recent suicide attempt occurred exclusively in the recent-NSSI group. Regarding NSSI phenomenology, onset averaged 9.88 years with an estimated average of 19 years elapsed since NSSI onset; banging/hitting (66.9%) and wound interference (62.7%) were more common than cutting (35.4%). Affect regulation and self-punishment were the most endorsed functions (motivations). Autistic people who recently engaged in NSSI are characterized by difficulties in self-compassion, elevated psychiatric symptoms, and pronounced STBs. While findings on NSSI methods in the non-autistic population are mixed, our sample showed meaningful divergence from typical non-autistic presentations, characterized not only by differences in methods but also by a distinctive childhood onset and a longer interval since NSSI onset. Future research should prioritize longitudinal investigations to clarify causal pathways across the lifespan.