Suicide prevention through better understanding and identification of interpersonal risk factors and building strengths

Abstract

Introduction: Suicide bears a significant public health impact worldwide, and there is a need for better identification of suicide risk and protective factors and more accurate prediction of its development. The aim of the present thesis was to promote suicide prevention through: (1) better understanding and identification of interpersonal risk factors for suicide, as outlined by a recent predictive model of suicide: the Interpersonal Psychological Theory of Suicide (IPTS; Joiner, 2005; Van Orden et al., 2010), and (2) building interpersonal strengths. Methods: A systematic review was conducted to identify support for the IPTS predictions regarding suicide ideation and suicide attempt. Based on the results of this review, several studies were conducted to fill critical gaps in the literature base. This included: (a) a latent class study of 1,321 adults to test the generalisability of the IPTS predictions in a community sample, (b) a longitudinal study in an Australian clinical sample (n = 331) to test the IPTS predictions over time in a high-risk population, (c) a study to develop and validate a new self-report measure for thwarted belongingness (TBS) against the Interpersonal Needs Questionnaire Thwarted Belongingness subscale (INQ TB; Van Orden, Cukrowicz, Witte, & Joiner, 2012) and (d) a pilot study to investigate the feasibility of a university-based peer-support walking program in contributing to decreased interpersonal suicide risk in Australian university students. Results: The systematic review found mixed evidence across the theory’s main predictions. The effect of perceived burdensomeness on suicide ideation was the most tested and supported relationship. The theory’s other predictions, particularly in terms of critical interaction effects, were less strongly supported. Across studies testing the IPTS predictions (Chapters 3-5), the role and specificity of the two-way interaction between TB and PB on suicide ideation was supported in two community-based samples, but not supported cross-sectionally or longitudinally in a clinical sample. No support was found for the IPTS three-way interaction prediction. However, associations between the interpersonal risk factors and suicidality were consistently supported across the studies. Findings from the pilot controlled trial (Chapter 6) indicated that a university-based peer-support walking program contributed to increased levels of positive friendship social support (Cohen’s d = 0.82) and decreased levels of psychological distress (Cohen’s d = -0.32) in university students. Conclusions: Mixed findings regarding the two- and three-way IPTS interactions highlight the critical need for additional IPTS studies designed with the aim of overcoming existing methodological limitations before the full extent of the theory’s theoretical and clinical utility can be determined. Support for the interpersonal risk factors as main effects suggests that they may serve as valuable targets for suicide prevention and intervention more broadly. Future research utilising the best available and validated measures of the interpersonal risk factors is needed for better prediction of interpersonal suicide risk, and for use in the design and evaluation of connectedness-based suicide prevention/intervention programs to promote interpersonal strengths in the community. Show more