Self-harm is associated with considerable costs, individually, socially and economically, and therefore, understanding its etiology is critical in order to identify potential intervention targets. The current study was the first, to our knowledge, to examine mechanisms underlying the association between EAU and self-harm, while controlling for shared environmental and genetic influences. Broadly, prevalence rates of lifetime self-harm in the current study were comparable to those reported in meta-analytic work using adult samples (Nock et al. 2008;Swannell et al. 2014), but they were somewhat lower than those reported in adolescent samples (Nock et al. 2013;Swannell et al. 2014). This discrepancy between lifetime self-harm (and particularly NSSI) in adolescents relative to adults is perplexing, and potential explanations for this include recent increases in adolescent self-harm and/or retrospective reporting bias by adults, the latter of which is more consistent with existing literature (see Nock et al. 2008). The results of this study also confirm the established overlap between NSSI and SA (Hamza et al. 2012) (Hamza, Stewart, & Willoughby, 2012), as approximately 13% of those endorsing lifetime self-harm (i.e., 59 out of 450) reported a history of both SA and NSSI.
