A meta-analysis on the affect regulation function of real-time self-injurious thoughts and behaviours

Prominent theories suggest that self-injurious thoughts and behaviours are negatively reinforced by decreased negative affect. The present meta-analysis quantifies effects from intensive longitudinal studies measuring negative affect and self-injurious thoughts and behaviours. We obtained data from 38 of the 79 studies (48%, 22 unique datasets) involving N = 1,644 participants (80% female, 75% white). Individual-participant data meta-analyses revealed changes in affect pre/post self-injurious thoughts and behaviours. In antecedent models, results supported increased negative affect before nonsuicidal self-injurious behaviour (k = 14, 95% CI 0.09 to 0.31) and suicidal thoughts (k = 14, 95% CI 0.03 to 0.19). For consequence models, negative affect was reduced following nonsuicidal self-injurious thoughts (k = 6, 95% CI −0.79 to −0.44), nonsuicidal self-injurious behaviours (k = 14, 95% CI −0.73 to −0.19) and suicidal thoughts (k = 13, 95% CI −0.79 to −0.23). Findings, which were not moderated by sampling strategies or sample composition, support the affect regulation function of self-injurious thoughts and behaviours. In an individual-participant meta-analysis, including intensive longitudinal studies, Kuehn et al. find support for the hypothesis that self-injurious thoughts and behaviours are negatively reinforced by relief from negative affect.