The link between nonsuicidal self-injury and acquired capability for suicide: A longitudinal study.

Despite recent findings that nonsuicidal self-injury (NSSI) is a strong predictor of suicide attempts, little empirical attention has been given to the mechanism through which NSSI increases suicide risk. The present 2-wave longitudinal study represents the first critical test of Joiner's (2005) hypothesis that NSSI is linked to lower pain sensitivity and fear of death over time (i.e., NSSI leads to acquired capability for suicide). Undergraduate students (N = 782) at a midsized Canadian university completed measures of NSSI and acquired capability for suicide at 2 time points (1 year apart). Path analyses revealed that higher frequency of NSSI engagement in the past year was associated with greater acquired capability for suicide 1 year later, and that this link was unidirectional. This study provides the first longitudinal evidence that a potential mechanism for the link between NSSI and suicide attempts may be acquired capability for suicide, and suggests that targeting NSSI engagement could help to prevent individuals from acquiring the ability to enact more lethal forms of self-injury.