A test of the interpersonal-psychological theory of suicidal behaviour in a sample of mental health outpatients

Suicidality is a growing mental health problem, with statistics for South Africa being in line with global estimates. There has, however, been relatively little empirical advancement in the conceptualization of suicidal behaviour in recent years. Joiner’s interpersonal-psychological theory of suicidal behaviour is a relatively new theory that appears to hold promise for advancing our understanding of the mechanisms that underlie suicidal behaviour. The theory proposes that people die by suicide because they want to and because they can. This study sought to test two key hypotheses of the interpersonal-psychological theory of suicidal behaviour using a cross-sectional design and a sample of 239 mental health outpatients. Consistent with theoretical predictions, levels of suicidal ideation were significantly predicted by the interactive effects of high levels of thwarted belongingness and perceived burdensomeness in the presence of high levels of hopelessness in relation to both of these distressing states; with estimates of risk for suicide being most strongly predicted by the interactive effects of suicide ideation and an acquired capability for suicide. These findings are discussed in terms of their implications for theory, practice, and future research.