1. Brittney L. Assavedo, B.S. & Michael D. Anestis, Ph.D.
Examining the relationship between non-suicidal self-injury and suicidal desire: NSSI frequency and thwarted belongingness
Brittney L. Assavedo, B.S. & Michael D. Anestis, Ph.D.
University of Southern Mississippi
Introduction
Method
Hypotheses
Discussion
Prior research has established a significant association between non-suicidal self-injury (NSSI) and suicidal behavior (e.g. Whitlock & Knox, 2007). Indeed, NSSI history and frequency have been found to be stronger predictors of suicidal ideation and suicide attempts than other established risk factors (e.g. Andover & Gibb, 2010).
The interpersonal-psychological theory of suicidal behavior (IPTS; Joiner, 2005), which posits that an individual must have both desire (thwarted belongingness and perceived burdensomeness) and capacity for lethal self-harm (increased pain tolerance and diminished fear of death/bodily harm) in order to engage in a lethal suicide attempt, conceptualizes the role of NSSI in suicide as contributing to acquired capability through habituation to pain and increased fearlessness about death.
Self-injurers engage in NSSI primarily for automatic (i.e. intrapersonal) reinforcement (Nock & Prinstein, 2004). Moreover, engaging in NSSI for automatic negative reinforcement is associated with history of suicide attempts (Nock & Prinstein, 2005) and the tendency to engage in NSSI alone is a robust indicator of suicide risk (Glenn & Klonsky, 2009).
These findings suggest a potential role for NSSI that extends beyond capability and includes cognitive vulnerabilities.
This study examined a sample of undergraduates (n = 999) ranging in age from years (M age = 21.18).
Participants completed a series of self-report questionnaires.
Predictor Variable
NSSI Frequency: The Deliberate Self-Harm Inventory (DSHI; Gratz, 2001)
Covariates
BPD Symptoms: Shortened version of the Borderline Symptom List (BSL; Bohus et al., 2009)
Depression: The Depression, Anxiety, Stress Scale (DASS; Lovibond & Lovibond, 1995).
Outcome Variable
Thwarted Belongingness & Perceived Burdensomeness: The Interpersonal Needs Questionnaire (INQ; Van Orden, Witte, Gordon, Bender & Joiner, 2008; Van Orden et., al 2012).
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). Results were consistent with our hypotheses.
The significant positive association between NSSI frequency and belongingness implies that individuals frequently engaging in NSSI are vulnerable to experiencing elevated levels of thwarted belongingness, as social isolation, shame and a sense of limited control over one’s own emotions are highly relevant to interpersonal connections.
The non-significant association between NSSI frequency and perceived burdensomeness implies that frequent engagement in NSSI does not directly result in elevations in perceived burdensomeness. NSSI behavior itself does not necessarily impact an individual’s sense that he or she makes contributions to society above and beyond the effects of psychopathology. In this sense NSSI and burdensomeness would be reflections of psychopathology.
The results suggest that the frequency of engagement in NSSI is a strong predictor of suicidal desire. Moreover, these findings suggest that the relationship between NSSI and suicide is not strictly limited to acquired capability, but also includes a component of suicidal desire.
Frequency of NSSI would be positively associated with thwarted belongingness.
Frequency of NSSI would not be significantly associated with perceived burdensomeness.
Results
N = 198
N = 797
Two hierarchical multiple regression analyses were conducted to examine the main effects of NSSI on both belongingness and burdensomeness.
Intercorrelations for variables used in primary analyses
(N = 999) 1 2 3 4 5 6
1. Belongingness -
2. Burdensomeness
.67**
3. NSSI Frequency
.27**
.24**
4. BPD Symptoms
.50**
.52**
.37**
5. Depression
.57**
.54**
.30**
.64**
6. Sex
-.087**
-.096**
-.026
-.030
-.063*
Note: * = p < .05; ** = p < NSSI = Normal score of NSSI frequency using Bloom’s formula.
After controlling for BPD symptoms, depression and sex NSSI frequency was significantly, positively associated with thwarted belongingness (t = 3.14, p = .002, f2 = .015).
Controlling for the same covariates NSSI frequency was not significantly associated with perceived burdensomeness (t = 1.23, p = .22, f2 = .0015).