Background Childhood maltreatment is a major public health issue and associated with self-harm in adolescents. Self-harm is the strongest recognised predictor of suicide. Associations between reduced pain sensitivity and childhood maltreatment have been reported. We have previously shown that pain hyposensitivity is a robust feature of adolescents living in residential care with self-harm. Here, we explore the relationship between adverse childhood experiences (ACE), self-harm, and pain sensitivity in this sample. Methods Forty-eight adolescents (13-17 years) completed the ACE 10-item scale and were tested using a standardised quantitative sensory testing (QST) protocol. Participants were categorised according to the subtypes of abuse experienced (e.g., physical versus sexual) and frequency of self-harm within the past year. Associations between subtypes of childhood maltreatment, self-harm, and pain sensitivity were examined using ordinal regression, linear regression and independent samples t-test. Results In our sample, history of sexual abuse was the strongest predictor of self-harm (p = .01). Those with experience of sexual abuse (n = 13) also showed significantly higher pain thresholds (p = .01). Those with experience of sexual abuse and the most frequent self-harm (n = 11) showed significantly higher pain thresholds compared to those without experience of sexual abuse (n = 10, p = .009). Limitations The cross-sectional study design does not allow us to establish causal relationships. Due to the limited sample size, findings should be interpreted as exploratory. Conclusions Based on a limited sample of 48, our findings suggest that a history of sexual abuse may have a unique relationship to self-harm and pain hyposensitivity. Longitudinal research is needed to estimate the predictive value of pain sensitivity as a potential biomarker to identify those at risk for self-harm and suicide
