The Relationship Between Non-Suicidal Self-Injury and Both Perceived Burdensomeness and Thwarted Belongingness

Prior research has established a connection between non-suicidal self-injury (NSSI) and suicidal behavior. The interpersonal-psychological theory of suicidal behavior (IPTS) posits that an individual must possess both a desire and capability for suicide in order to engage in a lethal suicide attempt. The IPTS conceptualizes the role of NSSI in suicidal behavior as contributing to an individual's acquired capability. The primary aim of this study was to investigate the relationship between frequency of engagement in NSSI and suicidal desire (thwarted belongingness and perceived burdensomeness). In this study, undergraduate students (n = 999) completed various questionnaires online. Results revealed a significant, positive association between NSSI frequency and thwarted belongingness and a non-significant association between NSSI frequency and perceived burdensomeness. Additionally, results indicated a significant indirect effect of NSSI frequency on burdensomeness and belongingness through depression and borderline personality disorder symptoms. The direct effect of NSSI frequency on belongingness remained significant; however, the direct effect of NSSI frequency on burdensomeness did not. These findings suggest that the relationship between NSSI and suicide is not strictly limited to acquired capability, but rather includes a component of suicidal desire.