Professionals

Review of the literature

Definition

Non-suicidal self-injury (NSSI) such as scratching, burning and cutting, is defined as "socially unacceptable behavior in which a person intentionally and directly inflicts physical self-harm without the intent to take their own life" (Claes, 2004, p.223). This definition excludes other types of behavior that include an element of self-harm. For example, indirect forms of self-harm, such as substance abuse and eating disorders, are distinguished from NSSI.

NSSI is also further distinguished from suicide (attempts), and this in several areas (for example, in terms of intention, method, lethality, function, etc.). NSSI and suicide attempts are viewed as different behaviors, yet are not completely independent (e.g., Nock, Joiner, Gordon, Lloyd-Richardson & Prinstein, 2006). For example, youth who self-injure are significantly 3 times more likely to develop suicide thoughts/ideations, and to undertake suicide (attempt) (Laye-Gindhu & Schonert-Reichl, 2005; Muehlenkamp et al., 2009; Whitlock et al. 2013; Zetterqvist et al., 2013). Research shows that the number of methods used to self-injure is related to the risk for suicide (Turner, Layden, Butler, Chapman, 2013). Injury through NSSI creates habituation to multiple forms of pain which lowers the threshold for engaging in serious suicidal behavior (Joiner, 2005). Specifically, research shows that 50% to 75% of individuals who self-injure ever attempt suicide (Nock, 2009). Important to keep in mind: Sometimes self-injury is also stated as an alternative to and avoidance of suicide (Claes & Vandereycken 2007b).

Prevalence

When looking at the prevalence of Huntington's disease in Belgium, we come across some disturbing figures. In adolescents, admitted to a psychiatric clinic, the rate of NSSI is between 40% and 80%. In non-clinical populations of adolescents, average lifetime prevalence of 18% is found (Baetens et al., 2011; Muehlenkamp et al., 2008).

Studies in clinical populations consistently report gender differences in prevalence of NSSI : girls there report 4 times more intentional self-injurious behavior than boys. However, results in non-clinical populations are less unambiguous in terms of gender differences: Although there are studies that conclude that NSSI is more frequent in girls than in boys (Laye-Gindhu & Schonert-Reichl, 2005; Nixon, Cloutier & Jansson, 2008;), most studies do not find a significant gender difference in prevalence (Baetens, Claes, Willem, Muehlenkamp & Bijttebier, 2011; Claes, Luyckx & Bijttebier, 2014; Hilt et al, 2008; Muehlenkamp, Williams, Gutierrez & Claes, 2009). However, we do see a clear gender difference regarding certain NSSI characteristics. For example, girls/women more often report a younger onset age, more severe injuries, and more heterogeneity in terms of frequency and switching between NSSI methods is recorded (Andover et al., 2010; Whitlock et al., 2010). In contrast, men report a greater sense of control over their self-injury than women. A consistent gender difference is also found in terms of method: the most commonly reported method for women was cutting and scratching, for men self-hitting (Baetens et al., 2011; Barrocas et al., 2012; Whitlock et al., 2010).

The risk of engaging in NSSI is highest during the adolescent years (Favazza & Conterio, 1988; Hjelmeland & Groholt, 2005; Llyod-Richardson et al., 2007). The onset age of NSSI shows a bi-modal peak, with the likelihood of starting NSSI highest at ages 13-14 and 18-19 (Plener et al., 2015).  Research shows the onset of NSSI in childhood (around age 10) is rather exceptional (1 to 2% of children) (Barrocas, Hankin, Young & Abela, 2012; Nock & Prinstein, 2004), and often related to severe trauma.

Adolescents self-injure for various reasons: coping with emotional overwhelm, discharging tension, self-punishment, reducing negative feelings, as a sign of power and control, dispelling loneliness, and so on. The functions of NSSI are very diverse and complex. This behavior is triggered or reinforced not by one but by multiple psychological states or thoughts; there is intra-individual variability in the functions of NSSI (Prinstein, Guerry, Browne & Rancourt, 2009). Self-injury can have several functions simultaneously, which may vary across method/time.

Nock and Prinstein (2004; 2005) propose a Four-Factor Model to categorize functions of self-injury. The different functions can be situated on two dimensions (reinforcement and motivation) and two valences (positive and negative). In research by Nock & Prinstein (2004 and 2005), adolescents mainly report regulating their emotions (automatic reinforcement). Only in 30% of cases do adolescents report that self-injury has a social reinforcement function (Baetens et al., 2011).

Co-morbidity

Research shows a clear difference between clinical and non-clinical populations in terms of co-morbidity.

Research in clinical populations shows that nearly 90% of adolescents (12-17 years old) who reported NSSI in the past year meet the criteria for at least one DSM-IV disorder. These include both internalizing and externalizing disorders and substance use disorders. More girls meet the criteria for an internalizing disorder, while more boys meet the criteria for an externalizing disorder. In addition, 70% of these adolescents report having ever made at least one suicide attempt (Nock et al., 2006). Increased comorbidity is also noted between NSSI and eating disorders (Claes & Muehlenkamp, 2014).

Studies in non-clinical populations show some comorbidity with drug and nicotine use, sexual risk behaviors, deviant eating habits, and negative self- and body image (Hilt et al., 2008). In addition, in the nonclinical population, NSSI has also been found to be associated with depressed mood, problems with affect regulation, and attention and impulsivity problems (Nixon et al., 2008). In non-clinical populations, an average of 35% meet criteria for a psychiatric diagnosis (e.g., Gollust, Eisenberg, & Golberstein, 2008). Baetens et al. (2012) conclude that NSSI in non-clinical populations may be more likely to be a manifestation of general psychological stress, and not necessarily accompanied by a psychopathological disorder.

Risk factors

International literature reports several biological, environmental and individual risk factors (psychological, emotional, cognitive) that increase the risk of NSSI in adolescence.

Biologically, deficits in the limbic system and the serotonergic system are reported. Furthermore, experiments show a difference in endogenous opiate system: for example, adolescents who self-injure feel less pain than adolescents who do not self-injure. Furthermore, one finds a biological vulnerability in the arousal system.

In addition to biological factors, environmental factors play a role in the development of NSSI in adolescence. A significant number of adolescents who self-injure report a life-altering event. Examples of such events include neglect, physical and emotional abuse, serious illness or death within family or friend circles, relationship breaks. These experiences bring feelings of fear, anger, powerlessness and helplessness. Life-altering events can lead to decreased well-being and negative self-image. NSSI is a way for some to cope with these overwhelming feelings.

Furthermore, risk factors in the family are reported in international literature. One of the risk factors within a family situation is the suppression of the expression of emotions (Klonsky & Glenn, 2009a). Because emotions are not shown within the family, a child does not learn to deal with intense emotions in an adaptive manner. Furthermore, growing up in a broken family is a risk factor for NSSI in adolescence (Sourander et al., 2006). However, the link between divorce and NSSI is mediated by an increase in psychopathology in the divorced parents. Similarly, health problems of a parent are a risk factor (Sourander et al., 2006). Another risk factor is constituted by certain relational characteristics of the parenting situation: a parenting situation in which there is a lack of parental warmth and a high level of parental control play a role in the development of NSSI (Bureau, Martin, Freynet, Poirier, Lafontaine, & Cloutier, 2010; Martin, Bureau, Cloutier, & Lafontaine, 2011). Finally, insecure attachment is an important mediating risk factor (Ghandi et al., 2016).

Several studies show that temperament is a risk factor for NSSI. Claes and Vandereycken (2007b) indicate that an impulsive temperament often plays a role in the development of NSSI. Individuals with an impulsive temperament act before thinking about the consequences of their behavior. Klonsky and Muehlenkamp (2007) showed that people who self-injure experience more and more intense negative emotions than those who do not self-injure. In addition, when there are problems regulating negative emotions, the risk of NSSI increases (Klonsky & Glenn, 2009a)

A negative self-image would also contribute to NSSI. In their study, Claes, Houben, Vandereycken, Bijttebier and Muehlenkamp (2010) demonstrated a link between negative self-image and NSSI. Adolescents who self-injure often describe themselves as less intelligent and less attractive than those who do not self-injure. Another risk factor associated with NSSI by Klonsky and Muehlenkamp (2007) is self-criticism. Individuals who self-injure are often very critical of themselves. They also often feel strong self-hatred or anger directed at themselves.

Finally, depression can also be seen as a risk factor. When people are depressed, they often feel lonely, helpless, weak and afraid of being abandoned (Luyten, Blatt, & Corveleyn, 2005). Moreover, when this depression is accompanied by self-criticism, the person in question feels especially ashamed, worthless, and feelings of guilt and a chronic fear of criticism often rear their head. Several studies have shown a link between depression and NSSI (Glassman, Weierich, Hooley, Deliberto, & Nock, 2007; Haw, Hawton, Houston, & Townsend, 2001; Klonsky, Oltmanns, & Turkheimer, 2003). Presumably, this relationship is a result of poor emotion regulation strategies (Hilt, Cha, & Nolen-Hoeksema, 2008). Depressed individuals would have a harder time regulating their emotions. NSSI is then presumably posed to regulate these difficult emotions.

Consequences

The long-term consequences of NSSI are feelings of guilt, shame, worthlessness. Moreover, NSSI has a negative impact on the social environment: parents, friends, teachers may react emotionally (from their powerlessness). Afterwards, any scars continue to remind the youth of the difficult moments when they self-injured. Research shows that these negative consequences increase the risk of relapse, as well as suicide / suicide attempt up to 60%.

It is then important to give young people the opportunity to talk about NSSI, and to support them in seeking appropriate help.