Approximately 18% of adolescents have, without suicidal intent, deliberately engaged in self-injury (Muehlenkamp et al.
2012). For many people who self-injure, NSSI is an adolescent-limited behaviour (Klonsky
2011). The onset of NSSI typically ranges from 12 to 15 years old (Andover et al.
2010; Nixon et al.
2008), prevalence peaks at approximately 15 to 16 and then begins to decline during young adulthood (Plener et al.
2015). Converging evidence from self-report (Edmondson et al.
2016), ecological momentary assessment (Muehlenkamp et al.
2009), and experimental manipulation (Franklin et al.
2010) demonstrates that non-suicidal self-injury (NSSI) functions as a strategy to manage emotional distress. …