Non-suicidal self-injury-related differences in the experience of negative and positive emotion

Objective: Emotional experience is argued to contribute to the initiation and maintenance of non-suicidal self-injury (NSSI). We investigated whether individuals with/without a history of NSSI differed in their dispositional experience of negative and positive emotion, as well as their state responses to negatively and positively-valenced movie clips. Method: Undergraduates (n = 214, Mage = 21.33, 73.8% female, 35.5% reporting NSSI) completed measures of NSSI and dispositional emotional experience. Participants also viewed a sad and amusing movie clip, and provided sadness/amusement ratings at seven time-points. Results: Relative to participants with no history of self-injury, participants reporting NSSI indicated more reactivity, intensity, and perseveration of trait negative emotion; however, differences were negated after adjusting for mental illness. Unexpectedly, individuals with a history of NSSI responded less intensely to the sad clip, although they demonstrated perseveration of sadness over time. Participants reporting NSSI also indicated less reactivity, intensity, and perseveration of trait positive emotion and, in response to the amusing film, reported less amusement at all time-points. Conclusions: Considering different dimensions of negative and positive emotion may enhance understanding of NSSI. Future research should disentangle which dimensions of emotional experience are unique to NSSI and which are shared with mental illness more generally.