Aberrant pain perception in direct and indirect non-suicidal self-injury: An empirical test of Joiner's interpersonal theory

Using a community sample (N = 148) we examined pressure pain perception in 3 study groups - people who engaged in non-suicidal self-injury, people who engaged in indirect forms of self-injury, and non-self-injuring controls. In so doing we tested hypotheses derived from Joiner's (2005) interpersonal theory of suicide. Consistent with previous studies and with Joiner's model, people who engaged in NSSI endured pain for significantly longer than non-self-injuring controls. Importantly, pain endurance in the Indirect self-injury group was comparable to that found in the NSSI group and significantly elevated relative to controls. This pattern of results suggests that abnormal pain perception may not be specific to forms of self-injury (e.g., NSSI) that involve immediate physical pain (e.g., cutting). Our findings further suggest that the concept of acquired capability for suicide might have relevance for both direct and indirect forms of self-injurious behavior.