The Impact of Emotional Arousal on Physical Pain and Numbness in Individuals Who Engage in Non‐Suicidal Self‐Injury

INTRODUCTION: Non-suicidal self-injury (NSSI) is commonly understood as a behavior that serves to regulate affect, yet less is known about how specific emotional states relate to physical sensations during NSSI. This study examined whether high-arousal negative emotions (HANEs) and low-arousal negative emotions (LANEs) before NSSI were differentially associated with physical pain and numbness during NSSI episodes. METHODS: Forty adolescents and emerging adults with recent NSSI completed a 14-day ecological momentary assessment protocol. Across 143 NSSI episodes, participants reported negative emotions immediately before NSSI and physical pain and numbness during NSSI. Linear mixed-effects models separated within-person emotion fluctuations from between-person differences. RESULTS: At the between-person level, individuals who reported higher average HANEs before NSSI reported greater pain and lower numbness during NSSI, whereas individuals who reported higher average LANEs reported lower pain and greater numbness. At the within-person level, episodes preceded by higher-than-usual LANEs were associated with greater pain, but no within-person emotion predictors were significantly associated with numbness. CONCLUSION: Findings suggest that high- and low-arousal negative emotions may correspond to distinct somatic experiences during NSSI, highlighting the importance of assessing both emotional antecedents and physical sensations during self-injury.