From noise to signal: Interpreting heterogeneity in ADHD-related non-suicidal self-injury

Meta-analytic evidence indicates that non-suicidal self-injury (NSSI) is substantially more prevalent among individuals with attention-deficit/hyperactivity disorder (ADHD), yet estimates are accompanied by extreme between-study heterogeneity and preliminary sex-stratified differences. In this Letter to the Editor, we argue that such heterogeneity should be interpreted not only as a methodological limitation but also as a clinically meaningful signal of multiple, context-dependent pathway configurations linking ADHD and NSSI. We propose a pathway-oriented framing in which ADHD related NSSI vulnerability may cluster around impulsivity/emotion dysregulation, internalizing burden, and context-sensitive factors that shape detection and help seeking. We further caution that sex-related estimates may be influenced by gender differences in symptom expression, diagnostic timing, and measurement practices, and therefore require explicitly gender-sensitive designs. Finally, we outline how this interpretation can strengthen translation by supporting person-centered, context sensitive screening-pairing routine NSSI assessment with brief internalizing probes-without extending the scope of the original meta-analysis.