Experimental studies suggest alcohol facilitates deliberate self-harm (DSH). One explanation might be that alcohol increases pain tolerance (PT), which may then lead to DSH. This study aimed to examine whether PT mediated the relationship between alcohol and DSH. Further, alcohol is neither necessary nor sufficient to self-harm. Given past non-suicidal self-injury (NSSI) is a good predictor of future DSH, NSSI may moderate these relationships. This study also aimed to examine if mediation was conditional upon past NSSI. Participants (106 men and 104 women) reported on past NSSI and received a drink sufficient to produce target blood-alcohol content (BAC = .000%, .050%, .075%, or .100%). Participants completed a behavioral measure of DSH. Results revealed that the association between BAC and DSH was mediated through PT. Additionally, past NSSI moderated the path between PT and DSH but did not affect the path between BAC and PT. Clinical implications and limitations are discussed.

Alcohol intoxication has been associated with deliberate self-harm (DSH). However, the mechanisms underlying this relationship are poorly understood. The primary purpose of this study was to examine pain tolerance (PT) as a potential mechanism underlying the relationship between alcohol intoxication and DSH. The secondary aim was to determine if borderline personality (BPD) features moderate the mediational model. This model was tested using secondary data of 210 non-alcohol dependent men and women (Mage = 26; SD = 6.97) who consumed a drink containing sufficient alcohol to produce average blood alcohol concentration (BAC) ranging from .000 through .100. Participants then engaged in a validated laboratory self-harm task (The Self-Aggression Paradigm). Results supported the notion that PT mediates the relationship between BAC and DSH. BPD moderated the indirect path between PT and DSH but not BAC and PT. This effect was prominent for men versus women. Clinical implications and future directions are discussed.