A Study on Configurational Profiles of Vulnerability Conditions for Frequency-Based Non-Suicidal Self-Injury Severity Among University Students

Non-suicidal self-injury (NSSI) constitutes a significant public health issue among university students. Existing research commonly compares individuals with and without a history of NSSI; however, few studies have explored how multidimensional vulnerability conditions co-occur in relation to NSSI severity among individuals who have already engaged in NSSI. This study adopts a configurational approach to examine how eight antecedent conditions—family environmental risks (FERs), school environmental risks (SERs), vulnerable personality traits (VPTs), traumatic experiences (TEs), emotional symptoms (ESs), hazardous behaviors (HBs), negative life events (NLEs), and social support (SS)—co-occur in association with NSSI severity among university students with prior NSSI experiences, with the aim of generating hypotheses for future screening research. In total, 776 Chinese university students (61.3% female; Mage = 19.50, SD = 1.29) reporting at least one NSSI episode in the past year were recruited. Questionnaire data were collected using the Non-Suicidal Self-Injury Scale, Negative Life Events Scale, Social Support Scale, and a self-developed scale measuring distal vulnerability conditions of NSSI. A fuzzy-set qualitative comparative analysis (fsQCA) was adopted to explore how eight antecedent conditions relate to the frequency-based NSSI composite score in this sample. One stable configuration is associated with high NSSI severity. When four prominent conditions—school environmental risks (SERs), traumatic experiences (TEs), emotional symptoms (ESs), and hazardous behaviors (HBs)—co-occur, accompanied by elevated negative life events (NLEs) and limited social support (SS), university students are more likely to exhibit high NSSI severity. Three equifinal configurations are identified for non-high NSSI severity. The first is characterized by low levels of traumatic experiences (TEs), emotional symptoms (ESs), and hazardous behaviors (HBs), together with few negative life events (NLEs), and is associated with non-high NSSI severity regardless of external social support (SS). The second and third are characterized by the co-occurrence of high social support (SS) alongside attenuated risk conditions. The configurations associated with high NSSI severity are not simply mirror images of those for non-high NSSI severity. Emotional symptoms (ESs) function as a core distinguishing condition between the two outcomes. Social support (SS) exhibits heterogeneous co-occurrence patterns rather than uniform associations with NSSI severity.