Non-suicidal self-injury (NSSI) among emerging adults: Sub-group profiles and their clinical relevance.

Abstract Background: High prevalence rates and variations in patterns of non-suicidal self-injury (NSSI) necessitate the identification of profiles of distinct sub-groups of self-injurers. Aim: To identify homogenous sub-groups of NSSI in a community-based sample of emerging adults. Method: Data was collected using a cross-sectional survey design from a sample of 1,574 emerging adults aged 18-25 years, via multi-stage sampling. Cluster analysis using the k-medoid partitioning method was used to identify homogenous sub-groups in the sub-sample of 353 self-injurers. Follow-up analysis was conducted on measures of self-criticism, brooding-rumination, emotion regulation difficulties, experiential avoidance, psychological distress, attachment style and perceived social support to explore the validity of the clusters. Results: Five homogenous sub-groups were identified; Multimethod, Exclusively Severe, Female Minor, Male Minor and Experimental NSSI. The sub-groups showed distinct patterns of NSSI behaviour, differing on the basis of gender, severity, frequency, diversification, age of onset and functions of NSSI. The Multimethod and Exclusively severe NSSI group members showed significantly higher psychological distress and emotion regulation difficulties. Conclusion: Identification of distinct sub-groups highlights the heterogeneity in NSSI behaviour. This has implications for comprehensive assessment frameworks, early identification of more vulnerable groups of self-injurers, and planning of targeted interventions.