MARCO LEGAL

The Proposed Criteria for NSSI in the DSM-5 (Table 2) specifies that the behaviour is repetitive in nature, requiring five acts to have occurred within the past

132 year to fulfil this diagnosis (APA, 2013). The literature consistently demonstrates that NSSI is a predominantly repetitive behaviour (Favazza & Conterio, 1989; Heath et al., 2008; Lloyd-Richardson et al., 2007; Madge et al., 2008; Muehlenkamp & Gutierrez, 2007; Whitlock et al., 2006; Whitlock et al., 2011). Studies on both adolescent

(Hasking, Andrews, & Martin, 2013; Laye-Gindhu & Schonert-Reichl, 2005; Nixon et al., 2008; Zetterqvist et al., 2013), and college based samples (Hamza & Willoughby, 2014; Heath et al., 2008; Whitlock et al., 2006; Whitlock et al., 2011) indicate that the majority (approximately 70% to 80%) of adolescents and young adults engage in

multiple acts of NSSI. Lloyd-Richardson et al. (2007) reported that adolescents engaged in an average of 12.87 acts of NSSI, whilst 41% of the adolescents in the Zetterqvist et al. (2013) study indicated that they self-injured 11 or more times. Similar results have been found in college samples, with Hamza and Willoughby (2014) ascertaining that 24% of college students self-injured 5 – 10 times, 33% engaged in 11 – 50 acts of NSSI, 7.1% self-injured 51 – 100 times, and 14.2% reported over 100 incidents of NSSI.

7.2.1 The Relationship Between Method and Repeated Engagement in NSSI

The likelihood of repeated engagement in NSSI has been associated with the number and different types of methods, and the reasons for self-injuring by Madge et al. (2008). Repeated experience with NSSI was reported by 59% of adolescents who solely used cutting as their modus operandi (Madge et al., 2008). Similarly Miller et al. (2013), found that of those admitted to hospital for NSSI or DSH, individuals who employed cutting were more likely to be readmitted in the future than those who used other

methods of DSH. Madge et al. (2008) and Whitlock et al. (2011) both reported that 63% of their respective samples who engaged in repeated NSSI used multiple methods to

133 self-injure. Whilst it is reasonably intuitive to hypothesise that with repeated

engagement in NSSI the number of methods employed to self-injure may increase, this is an aspect of NSSI practice that has been underexplored in the literature to date.

7.2.2 The Experience of Pain

“…every pain contains in itself the possibility of a pleasurable sensation”

(Freud, 1910, p. 22)

The degree of pain experienced during self-injury has long been of interest to researchers. This is an artefact of the early clinical studies using samples of patients diagnosed with BPD. As these studies found that individuals who self-injured in a dissociative state typically experienced little or no pain during the act of NSSI (Bohus et al., 2000; Kemperman, Russ, Clark, Kakuma, Zanine, & Harrison, 1997; Russ, Clark, Cross, Kemperman, Kakuma, & Harrison, 1996; Russ, Campbell, Kakuma, Harrison, & Zanine, 1999). The past two decades have produced a marked increase of NSSI research in nonclinical samples, with studies revealing that between 13.1% (Plener et al., 2013) and 29% (Favazza & Conterio, 1989) of individuals experienced no pain during the act of NSSI (Murray, Warm & Fox, 2005: Polk & Liss, 2009). Whilst, 11.5% (Plener et al., 2013) to 43% (Murray et al., 2005) of individuals indicated, that they often or always felt pain during acts of NSSI. Lloyd-Richardson et al. (2007) confirmed, that

adolescents who engaged in moderate or severe NSSI were more likely to experience pain during their self-injury, than those who engaged in minor NSSI. Exploring the actual level of pain experienced, estimates have varied from 3.2% (Polk & Liss, 2009),

134 8% (Hilt, Nock, Lloyd-Richardson, & Prinstein, 2008), and 10% (Favazza & Conterio, 1989) of participants disclosing they experienced great pain when self-injuring.

Whilst Emerson (1914, p. 51) originally contended “the pain element in itself may be regarded as almost negligible” in self-mutilation, contemporary research indicates that pain may actually serve multiple functions in NSSI. Furthermore, it appears that the sensation of pain is a salient feature of NSSI to many individuals who engage in this behaviour (Nock & Prinstein, 2004). It can transform emotional pain into something physical and tangible (Polk & Liss, 2009), or offer a distraction from

intolerable affect (Winchel & Stanley, 1991). The pain may also act as an immediate reminder to the individual who feels numb, that they are alive and can feel something, even if it is simply the sensation of pain (Nock & Prinstein, 2004; Polk, 2009).

Similarly, pain may act as a catalyst to either induce one into - or bring someone out of - a dissociative state (Brown, Comtois, & Linehan, 2002). Regardless of the function that pain performs in NSSI, the experience of pain appears to have a different meaning for those who self-injure, as they willingly endure exposure to painful stimuli (Hooley et al., 2010).

Individuals who self-injure have predominantly demonstrated higher pain analgesia than non-self-injurers, across both adult and adolescent samples (Franklin, Hessel, & Prinstein, 2011; Glenn, Michel, Frankin, Hooley & Nock, 2014; Hooley et al., 2010; Koenig, Thayer, & Kaess, 2016). More specifically, self-injurers generally exhibit higher pain thresholds (how long it takes until a stimulus registers as painful) and pain tolerances (how long a painful stimulus is endured before it is terminated) (Franklin, Hessel, & Prinstein, 2011; Hamza, Willoughby, & Armiento, 2014; Hooley et al., 2010; Koenig et al., 2016). Interestingly, Joiner’s (2005) theory of interpersonal-

135 psychology has been proposed to explicate the differences in pain analgesia between those who self-injure and those who do not. In particular, that individuals who self- injure have a decreased aversion to pain, and are less intimidated by the thought of anticipated pain. Secondly, that repetitive acts of NSSI result in a habituation effect, increasing one’s pain threshold and tolerance levels (Hooley, 2010; Nock, 2010). However, a number of recent studies have not supported this hypothesis, finding that self-injurers were not more likely to engage in provocative and painful events (PPEs: e.g., getting a tattoo, contact sports) than non-self-injurers (Franklin et al., 2011; Hamza, Willoughby, & Armiento, 2014). In addition, the habituation hypothesis has found mixed support, with research indicating that the frequency of NSSI is not related to the experience of pain (Franklin et al., 2010; Franklin et al., 2013). Finally, Joiner (2005) originally proposed his theory of interpersonal-psychology to explicate the relationship between NSSI and subsequent SAs, not the relationship between pain and NSSI, to which it has recently been applied.

Recent research has found a relationship between self-criticism, NSSI and pain analgesia (Glenn et al., 2014). Based on this, several studies have suggested that individuals who are highly self-critical are more willing, or believe they are more deserving of enduring pain, as it is consistent with their self-view (Hooley, 2010). More specifically, that self-critical individuals employ NSSI as a mechanism for self-

punishment or the reduction of guilt (Hooley et al., 2010; St Germain & Hooley, 2012). Several important limitations exist in these recent studies on pain and NSSI, including small sample sizes in each of the experimental groups (Franklin et al., 2010; Glenn et al., 2010; Hamza, Willoughby & Armiento, 2014; Hooley et al., 2010; Hooley & St Germain, 2015). Fundamentally, we cannot be sure that the measures of pain

136 assessment (i.e., algometer pressure devices or cold-pressor tasks) adequately replicate the pain sensation of NSSI, created by the participant’s chosen method of self-injuring (Glenn et al., 2014; Hamza, Willoughby & Armiento, 2014). Aside from Hamza, Willoughby and Armiento (2014), the majority of these studies also did not include a manipulation to alter the affect of participants, which typically occurs preceding an act of NSSI (Glenn et al., 2014; Hooley & St Germain, 2015; McCoy, Fremouw, &

McNeil, 2010). As such Glenn et al. (2014) contests that results may be reflecting trait - as opposed to state - differences in pain analgesia. This is a developing area of research in NSSI warranting further exploration, and longitudinal studies could aid in clarifying questions of causality. Despite the increased research into the experience of pain and NSSI, it remains unclear why those who engage in NSSI demonstrate greater pain analgesia than controls (Glenn et al., 2014).