Nonsuicidal self injury among young adults and adolescents: Historical, cultural and clinical understandings

ABSTRACT

This article reviews the nature and prevalence of nonsuicidal self-injury (NSSI) and suggests how it can be better recognized and treated in the mental health community. Throughout history, NSSI has been a core element of many types of rituals (e.g. cultural, religious, spiritual, and healing rituals) and is now also regarded as a pathological expression of emotional pain, particularly in Western cultures, where its occurrence has increased dramatically since the 1980s. NSSI involves the direct and deliberate self-infliction of bodily harm without suicidal intent. Self-injury can be viewed as a distinct mental health disorder, a defining criterion of other mental disorders, or a transient response to trauma or stress. Notwithstanding its etiology, NSSI should become a more salient aspect of psychiatric evaluation and intervention considering its frequency of occurrence and deleterious consequences, especially among young people. The current article consists of six sections that describe the terminology associated with NSSI; its general prevalence, measurement, and variability (age, race, and gender); its relationship with other psychiatric illness; and its diagnosis and treatment.

KEYWORDS:

• Borderline personality disorder
• cutting
• nonsuicidal self-injury
• self-harm

This article reviews the nature and extent of nonsuicidal self-injury (NSSI) prevalence and suggests how NSSI can be better recognized and treated in the mental health community. Throughout history, NSSI has been a core element of many types of rituals (e.g., cultural, religious, spiritual, and healing rituals) (Favazza, 2009). Notably, NSSI is also regarded currently as a pathological expression of emotional pain, particularly in Western cultures, where its prevalence has increased dramatically since the 1980s (Gluck, 2012; Nock & Favazza, 2009). The practice of NSSI involves the direct and deliberate self-infliction of bodily harm without suicidal intent (Favazza, 2011). Self-injury can be viewed as a distinct mental health disorder, a defining criterion of other mental disorders, or a transient response to trauma or stress. Notwithstanding its etiology, NSSI should become a more salient aspect of psychiatric social work evaluation and intervention, considering its prevalence and deleterious consequences, especially among young people.

Review parameters

The literature contains a wide range of clinical and empirical findings on NSSI. The character and corpus of NSSI research lend itself to a descriptive inquiry rather than an evaluative critique of research quality, as performed in Cochrane or meta-analytic reviews. Thus, no systematic or evaluative analyses of NSSI studies are presented in this review. The current review provides no commentary on the quality of the numerous investigations cited overall in this paper or even the smaller groupings of those investigations, which are heterogeneous in many aspects, including purpose and methodology (e.g., sampling, design, and analyses). To achieve comprehensiveness, the articles were identified through numerous search engines, such as PsychInfo, PubMed, Medline, Web of Science, PsychArticles, Scopus, PsychNet, and PsychiatryOnline. Databases were searched for eligible studies published in English between 1990 and 2022. The following combinations of search terms were employed: self-harm, self-injury, nonsuicidal self-injury, NSSI, or deliberate self-harm, as well as epidemiology, comorbidity, gender, internalization/externalization, and DSM. The references in the articles identified in the search were also examined and generated a handful of relevant papers, including pre-1990 publications.

As a clinical condition, NSSI first appeared in the medical literature more than 80 years ago (Menninger, 1938). Empirical studies on NSSI began in the 1980s and have grown steadily in frequency since then, using largely descriptive, comparative, and cross-sectional techniques. In addition, NSSI prevalence data are quite variable and unreliable because of definitional challenges stemming from the debate about NSSI as a distinct diagnostic category for inclusion in the Diagnostic and Statistical Manual of Mental Disorders (DSM), the broadly encompassing definitions of self-harm, with and without suicidal intent, as well as variations in measures of NSSI (Cipriano, Cella, & Cotrufo, 2017). NSSI prevalence data are cited in this paper but must be interpreted with some caution.

This paper is intended to advance the substantive knowledge and understanding of NSSI. The specific purpose of this review is to enhance NSSI-related clinical practices in the field of social work, which is a bulwark of mental healthcare. This review lays the foundation for further exploring NSSI as a symptom, sign, diagnostic criterion, and possible diagnostic category of interest to clinical practitioners in social work. We are keen on expanding and elucidating the dialogue on NSSI, as recent theories and empirical findings suggest that this behavior is often a critical precursor of death by suicide (Horváth, Mészáros, & Balázs, 2020; Joiner, 2005; Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006), which is a serious and growing mental health crisis in the United States (Stone, Mack, & Qualters, 2023).

Content of review

The current article consists of six sections. Section 1 presents the various terms that have been used interchangeably to describe or define NSSI. Section 2 discusses the general prevalence and variations in different types of NSSI, as well as differences by age, race, and gender. Section 3 describes the measurement of NSSI. Section 4 examines the risks and reasons for self-injury. Section 5 discusses NSSI in the context of other psychiatric illnesses. Finally, Section 6 provides guidance for assessing and treating NSSI in clinical settings.

NSSI definitions, terminologies, and types

NSSI descriptors

As a general term, NSSI describes the behavior alternately known as “nonsuicidal self-mutilation,” “self-wounding,” or “self-cutting” (Laye-Gindhu & Schonert-Reichl, 2005). Other commonly used terms for this behavior include “deliberate self-harm,” “parasuicide” (Nock, 2010, p. 341), and “self-mutilation” (Favazza, 1998). The definitions of NSSI have grown clearer and more consistent (Nock, 2010) as the behavioral health field has moved away from terms such as “self-mutilation” and “deliberate self-injury” because they can be perceived as stigmatizing or fail to reflect the nonsuicidal intent of these behaviors. According to current definitions, NSSI must involve intentional physical injury (other definitions also include psychological injury) in the absence of suicidal intent. Socially sanctioned forms of body modification, such as tattoos and body piercings for the purpose of self-adornment, are excluded from the definitions of NSSI (Nock & Favazza, 2009; Whitlock, 2010).

In addition, NSSI can be differentiated from other potentially risky or indirectly harmful behaviors performed with no self-injurious intent but for pleasure, enjoyment, or sustenance (e.g., eating high-fat foods or drinking alcohol (Nock, 2010). Any consequent harm from these actions are unexpected and unwanted (Nock, 2010 and referred to as indirect self-harm (Møhl, la Cour, & Skandsen, 2014). Similarly, risk-taking behavior occurs when “a person engages in a pleasurable behavior in which there is a small likelihood of a large amount of harm (e.g., skydiving, bungee-jumping)” (Nock, 2010, p. 342). Such behavior involves a calculated risk of harm, but the resultant harm is not the de facto motivation for the behavior. Although the methods of self-injury can vary, the risk factors and characteristics of those who self-injure appear to be similar across populations and times.

Methods of self-injury

NSSI has been proposed as one of three primary types of nonsuicidal behaviors. The other types include suicidal threats or gestures (e.g., behavior through which individuals lead others to believe they intend to die from the behavior when they have no intention of doing so) and self-injurious thoughts (e.g., having thoughts of engaging in self-injurious behavior but not acting upon such thoughts) (Nock, 2010). These other nonsuicidal behaviors can be distinguished from NSSI because NSSI involves the direct and deliberate destruction of body tissue in the absence of any observable intent to die (Nock, 2010).

The category of NSSI encompasses a wide variety of potentially dangerous acts, including skin cutting, carving, digging (parasitosis), pricking, scratching, or burning; head banging or hitting; castration, facial mutilation, or genital mutilation; auto-cannibalism; teeth extraction; hair pulling (trichotillomania); and wound aggravation (Briere & Gil, 1998; Favazza, 2011). Across all populations, the most common types of NSSI are self-cutting and self-carving with a knife or razor (Nock, 2010). Other common types of NSSI include burning, head banging, and hitting. Based on NSSI studies, 70–90% of self-injuring subjects reported that they had cut themselves, 21–44% reported having banged their heads or hit themselves, and 15–35% reported having burned themselves (Nock, 2009a).

Similar patterns of self-injury have also been observed among clinical populations, in which the most common form of NSSI is skin cutting, followed by burning and banging/hitting body parts (Klonsky & Muehlenkamp, 2007). These forms of self-injury are most often inflicted upon the extremities (arms and legs) and stomach (Klonsky & Muehlenkamp, 2007). Moderate forms of NSSI (e.g., cutting) are associated with a longer history of mental health disorders, more frequent hospitalizations, and more serious suicidal thoughts and behaviors compared with mild NSSI behaviors (e.g., picking at wounds) (Lloyd-Richardson, Perrine, Dierker, & Kelley, 2007).

Individuals who self-injure often use Most self-injurers use more than one method of self-injury and tend to repeat such behaviors (Caicedo & Whitlock, 2009; Herpertz, 1995). The categories of NSSI include major NSSI (i.e., self-injury resulting in serious injury or permanent loss of tissues or limbs), stereotypic NSSI (i.e., repeated rhythmic self-injury associated with an intellectual or developmental disability), compulsive NSSI (i.e., repeated self-injury with preoccupation and loss of self-control), and impulsive NSSI (i.e., episodic self-injury in immediate response to overwhelming frustration or stress) (Favazza, 2011).

Stereotypic NSSI (e.g., high-frequency head banging) occurs most frequently in people with intellectual or developmental disabilities (Nock, 2010). The types of NSSI that result in major injuries, such as single-episode castration or eye enucleation, are highly rare and likely to accompany episodes of severe mental illness with psychotic symptoms (Briere & Gil, 1998; Favazza, 2011; Nock, 2010). Stereotypic and psychosis-induced self-injurious behaviors have common features, that is, “there are significant differences in the form and severity, as well as the clinical populations in which [these behaviors] typically occur” (Nock & Prinstein, 2004, p. 886).

Prevalence of self-injury

People have been self-injuring for thousands of years (Nock, 2010). However, recent studies have suggested that the prevalence of NSSI may be increasing (Griffin et al., 2018; Wester, Trepal, & King, 2018). Self-reported lifetime engagement in NSSI is highest among adolescents and young adults and lowest among older adults (Swannell, Martin, Page, Hasking, & St John, 2014), a trend that can provide indirect evidence for the mounting prevalence of NSSI. Additional evidence of the increasing rate of NSSI can be found in surveillance system information on the number of emergency department presentations for non-lethal self-injury (both suicidal and nonsuicidal). These data show an upward trend in self-injurious behaviors over a 10–20-year period (Hawton et al., 2003; Nock, Wedig, Janis, & Deliberto, 2008).

Other studies have measured changes in the prevalence of NSSI by comparing the same population in the same setting across different periods (Wester, Trepal, & King, 2018). For example, two studies conducted in the same high school have shown that the reported rates of lifetime NSSI increased from between 7% and 16% (Muehlenkamp & Gutierrez, 2004) to 23% among students (Muehlenkamp & Gutierrez, 2004, 2007). The most recent increase in the prevalence of NSSI may be attributed to the COVID-19 pandemic, with early research showing a more substantial increase in NSSI rates among adolescents from 2020 to 2021 (an increase of approximately 10%) compared with those in 2011 to 2014 (an increase of approximately 3%) (Zetterqvist, Jonsson, Landberg, & Svedin, 2021).

Demographic characteristics and self-injury

Age

The rates of NSSI have remained consistently higher among adolescents and younger adults than among older adults (Nock, 2010). Among the former, the rates typically range between 13% and 45% (Lloyd-Richardson, Perrine, Dierker, & Kelley, 2007; Plener et al., 2009). The estimated lifetime prevalence of NSSI among adolescents worldwide is 18% (Muehlenkamp, Claes, Havertape, & Plener, 2012). Similarly, a meta-analysis by Swannell, Martin, Page, Hasking, and St John (2014) revealed that the worldwide prevalence of lifetime NSSI was 17% among adolescents, 13% among younger adults, and 5% among older adults. In the United States, from 1–4% to as many as 6% of adults have reported having engaged in NSSI (Klonsky, 2011). Several other studies have estimated that the rates of NSSI among adults range from 14% to 18% (e.g., Klonsky, 2011; Muehlenkamp, Claes, Havertape, & Plener, 2012).

The average age of onset for NSSI is between 12 and 15 years, and the highest rates of NSSI are among people aged between 14 and 24 years (Ammerman, Jacobucci, Kleiman, Uyeji, & McCloskey, 2018). In fact, 90% of youth who engage in self-injury begin doing so during their pre-adolescent or teenage years. Nevertheless, other inflictors of self-injury engage in such behaviors later in life (Gluck, 2012), whereas some begin self-injuring before age 12 (including children as young as age seven). Early-onset NSSI is associated with more severe and prolonged self-injury (Ammerman, Jacobucci, Kleiman, Uyeji, & McCloskey, 2018).

Race, Ethnicity, and Nationality

The prevalence of NSSI differs across racial and ethnic groups. For example, self-injury is more common among White people than non-White people (Klonsky, 2013). Other studies on race and NSSI have reported a higher prevalence of self-injury among Native American and Latino adolescents than among Black and White adolescents (Evans, Hawton, Rodham, & Deeks, 2005). Moreover, the rates of NSSI vary globally, with some countries reporting higher rates of NSSI than others. Specifically, the rates of NSSI among clinical samples from various countries have ranged broadly from 12% to 82% (Nock & Prinstein, 2004; Selby, Bender, Gordon, Nock, & Joiner, 2012). Countries with higher rates of NSSI include Canada (17% of 14–21-year-olds) and Finland (12% of 13–18-year-olds) (Laukkanen et al., 2009). Norway is an example of a country with a lower rate of NSSI (3% of adolescents). These differences are likely a reflection of general beliefs about body image and integrity as well as perceived social norms regarding the acceptability of suicide and self-harm (Quigley, Rasmussen, & McAlaney, 2017).

Gender

NSSI appears to be much more common among those that identify as female (Favazza & Conterio, 1989, Klonsky, 2013; Suyemoto, 1998). Several studies of gender differences have substantiated that there is a gender disparity (Laye-Gindhu & Schonert-Reichl, 2005). However, since the early 2000s, numerous studies have shown equal rates of NSSI among men and women (Gratz, 2001; Klonsky, 2011; Muehlenkamp & Gutierrez, 2007).

The methods of NSSI seem to vary by gender and ethnicity. For example, in a study conducted in the United Kingdom, White women were more likely to cut themselves than other gender and racial groups, whereas Black women were the most likely group to self-poison (Cooper et al., 2010). Overall, men are less likely to engage in self-cutting or poisoning than women (Cooper et al., 2010). Studies have also shown that men are more likely to punch, hit, or bruise themselves and provoke fights to become victims of battery than women (i.e., self-injury by proxy) (Rodav, Levy, & Hamdan, 2014). In addition, men are more likely to burn themselves than women (Rodav, Levy, & Hamdan, 2014). By contrast, women are more likely to cut, pinch, or scratch themselves, inflicting less visible and less severe injuries than men (Rodav, Levy, & Hamdan, 2014; Whitlock, 2010).

Differences in the definitions and measurements of NSSI may account for some of the gender-based and rate differences in the prevalence of NSSI (Nock, 2009b). Histories of self-injury among men and women appear to be similar. For example, NSSI engagers of both genders have been found to be more likely to have been reared in a single-parent household, have been a victim of sexual or physical abuse, or had a parent with a serious illness or disability compared with non-engagers (Gluck, 2012; Laye-Gindhu & Schonert-Reichl, 2005). Frequent NSSI engagers of both genders scored lower on measures of emotional expressivity than non-engagers.

Clinical Populations

The percentages of NSSI engagers found in clinical populations tend to be higher than in the general population (Glenn & Klonsky, 2013; Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006). For example, estimates have suggested that 21% of adult inpatient psychiatric patients have engaged in self-harm, and 8% have reported that they “often [engaged] in self-mutilation” (Briere & Gil, 1998, p. 613). Among adolescent inpatient psychiatric patients, between 40% and 60% are estimated to have engaged in NSSI (DiClemente, Ponton, & Hartley, 1991; Glenn & Klonsky, 2013), and one study demonstrated even higher estimates of NSSI within this group, ranging from 40% to 80%. In clinical samples of adolescents and young adults, the prevalence of self-injury has been found to range from 37% to 50% (Zetterqvist, Jonsson, Landberg, & Svedin, 2021).

Interpersonal and Developmental Factors

Engagers in NSSI also appear to experience interpersonal difficulties. For example, those that self-injure have been found to possess poor communication and social problem-solving skills (Nock & Menes, 2008; Photos & Nock, 2006). Engagement in NSSI typically emerges during adolescence – a period of transition from dependence to independence that increases interpersonal demands and expectations (Cohen, Tottenham, & Casey, 2013). With growing independence comes increased responsibilities, choices, and opportunities that can result in rewards or stressors (Hornor, 2016). Although most adolescents develop effective coping mechanisms to adapt to their changing lives, some are unable to deal with these changes in a productive manner and turn to self-injury as an adaptation strategy (Wadsworth, 2015).

Those who self-injure typically have family histories of suicide and self-injury (Hawton, Saunders, & O’Conner, 2012) and poor problem-solving and communication skills (Nock & Menes, 2008). They also tend to model instances of NSSI (social contagion) depicted in social and popular media (e.g., movies, books, and news reports) (Lewis, Heath, Michal, & Duggan, 2012; Whitlock, Eckenrode, & Silverman, 2006). Moreover, individuals that self-injure report heightened sensitivity to interpersonal stress or conflict and more difficulty expressing or regulating their emotions (Jacobson et al., 2015). In short, “self-harm [is] the end-product of a complex interplay between genetic, biological, psychiatric, psychological, social, and cultural factors” (Hawton, Saunders, & O’Conner, 2012, pp. 2,374).

Developmental factors can put youth at risk for NSSI (Burton, 2019). For example, those who suffer early childhood trauma and abuse – also known as adverse childhood experiences (ACEs) – are more likely to engage in NSSI during adolescence as capacities for emotional regulation that are often a function of persistent childhood distress, particularly disrupted caregiver attachment (Gonzales & Bergstrom, 2013). The emotional dysregulation that contributes to NSSI can stem from problematic relationships with caregivers and other attachment difficulties. ACEs (e.g., broken attachments and abuse) can predispose youth to high emotionality or dissociative states, in particular, causing them to engage in NSSI or other extreme behaviors as a means of expressing or regulating emotional states (Gonzales & Bergstrom, 2013). High levels of parental control and demandingness and low levels of warmth and affection, known as an authoritarian parenting style, can be risk factors for NSSI (Baetens et al., 2014).

Early research on NSSI has focused on its correlates using cross-sectional studies (Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006), whereas more recent research has explored risk factors in longitudinal designs (Fox et al., 2015) that are especially relevant for prediction, theory development, and treatment. For example, a 2015 meta-analysis of longitudinal studies assessed more than 160 NSSI risk factors and revealed that a prior history of NSSI was the strongest predictor of current self-injury, followed by a diagnosis of borderline or antisocial personality disorders and feelings of hopelessness (Fox et al., 2015). Other significant risk factors for NSSI included suicidal thoughts and behaviors, exposure to peer NSSI, depression and depressive symptoms, eating disorders, gender (female identifying), externalizing and internalizing disorders, and affect dysregulation (Fox et al., 2015).

Although the aforementioned and other NSSI risk factors are noteworthy, their overall effects “were weaker than anticipated and most significant risk factors did not result in large increases in the absolute odds of future NSSI” (Fox et al., 2015, p. 163). The strong correlates of NSSI identified in cross-sectional research, such as internalizing symptoms and emotional dysregulation (e.g., Glenn & Klonsky, 2011; Gratz & Roemer, 2004), were weaker predictors of NSSI in the meta-analysis (Fox et al., 2015). Therefore, the correlates of NSSI can help identify important components of this behavior but may be less powerful predictors over extended periods (e.g., 12 months). Nonetheless, these correlates have demonstrated stronger predictive effects over shorter follow-up periods (Fox et al., 2015).

Assessing NSSI

Incidents of self-injury are typically captured with structured and semi-structured interviews or questionnaires (Nock, 2010). Instruments that measure NSSI range from single-item, open-ended questions to lengthy questionnaires, in-depth interviews, and comprehensive checklists (Fox et al., 2015; Hunsley & Mash, 2007). Items can be designed to collect information about indirect self-harm (e.g., self-poisoning) or normative forms of self-harm (e.g., scratching, rubbing, wound picking, or skin pinching) (Fox et al., 2015). For example, the Alexian Brothers Urge to Self-Injure Scale (ABUSI) considers “normative” self-injurious behaviors but specifies that they must be administered with enough force to cause “bruising or bleeding” (Washburn, Potthoff, Juzwin, & Styer, 2015, p. 2).

The design and content of NSSI measurement tools are determined by the purposes of the evaluation, such as whether the evaluation will be used to document, chronicle, or understand the onset and maintenance of self-injury or for a combination of purposes (Nock, 2008, 2010). In addition, items that focus on the factors purported to contribute to the onset or maintenance of self-injury are often employed to monitor the rates of NSSI across different populations and times and examine the effectiveness of treatments for self-injury (Nock, 2010).

Documenting the presence of NSSI

Early Studies

Before the early 2000s, self-injury had been considered a mere harmful behavior rather than a symptom of a DSM-defined mental disorder. Hence, only the presence and characteristics of self-injury have been measured in early studies (Klonsky, Victor, & Saffer, 2014). At that time, there was no common set of NSSI-related symptoms and signs that researchers could incorporate into their instruments (Nock, 2010).

Suicide Attempt Self-Injury Interview (SASII), Self-Injurious Thoughts and Behaviors Interview (SITBI), and Deliberate Self-Harm Inventory (DSHI)

The instruments that have been designed to help capture the presence of self-injury include the SASII (Linehan et al., 2006), SITBI (Nock, Homberg, Photos, & Michel, 2007), and DSHI (Gratz, 2001). The reliability, validity, and clinical utility of these and other NSSI measures have been reviewed elsewhere (see Nock et al., 2008a).

The DSHI is a 17-item behavior-based self-report questionnaire that defines self-injury as the deliberate and direct destruction or alteration of body tissue without conscious suicidal intent but with a resultant injury severe enough to damage the tissue (e.g., scarring) (Gratz, 2001). The DSHI is used to explore various aspects of deliberate self-injury, including the type, duration, severity, and frequency. While completing the DSHI, respondents indicate whether they have engaged in 15 types of deliberate self-injury by answering questions such as “Have you ever intentionally (i.e., on purpose) burned yourself with a cigarette?” and “Have you ever intentionally (i.e., on purpose) carved words into your skin?” The DSHI also includes an open-ended question that asks respondents to report any self-injurious behaviors not listed. The 15 acts of self-injury covered by this measure “were derived from clinical observations, testimonies of self-injurers, and common behaviors reported in the literature” (Gratz, 2001, p. 255).

Measuring the progression

SASII

As noted above, early NSSI research has mainly concentrated on the presence of self-injury rather than on self-injury over time (e.g., days, weeks, or months) (Nock, 2010). Although, historically, instruments for monitoring self-injury have required further measurement and evaluation in clinical settings as well as additional research to establish strong validities and reliabilities (Linehan et al., 2006; Nock, 2010), several tools now contain items that help track long-term self-injurious behaviors. For example, the SASII has been employed to chart the frequency of self-injury at four-month intervals. In one study, the SASII was incorporated into an evaluation of treatment effectiveness in a population of women who engaged in suicidal and self-injurious behaviors (Linehan et al., 2006). Generally, tools for tracking self-injury over time (e.g., days, months, years, or a lifetime) also include items designed to collect information on the age of onset, recency of the last episode, methods of self-injury, and other parameters (Nock, 2010).

Diaries

In some studies, a diary card has been used to capture information about daily self-injurious thoughts and behaviors in clinical settings (Linehan, 1993). Diary cards have also been adopted to monitor self-injurious thoughts and behaviors for research purposes (e.g., Wallenstein & Nock, 2007). However, technological advances have enhanced the capacity for monitoring self-injury in this manner, for example, electronic diaries have been developed to track self-injury real-time (Muehlenkamp et al., 2009; Nock, 2009a).

Understanding function and motivation

SASII, SITBI, and Functional Assessment of Self-Mutilation (FASM)

Measurement tools for NSSI are also utilized to understand how self-injurious behavior can develop and be controlled (Nock, 2010). For example, the SASII (Linehan et al., 2006), SITBI (Nock, Homberg, Photos, & Michel, 2007), and FASM can be used to collect self-reports of the reasons for and the immediate antecedents and consequences of self-injury. With these instruments, researchers and clinicians have attempted to define the factors that prompt and reinforce such behaviors.

Inventory of Statements About Self-Injury (ISAS) and FASM

Other tools that measure NSSI focus on the functions of or reasons for NSSI. One such example is the ISAS (Klonsky & Olino, 2008), which evaluates the two general functions of NSSI: interpersonal and intrapersonal. More specifically, the ISAS is used to measure 13 purposes of NSSI (39 items in total, with three items per function), as well as the lifetime frequency of 12 NSSI behaviors, including banging, hitting, carving, hair pulling, and wound picking. The resultant measure is comprehensive, examining many of the functions of NSSI discussed in the literature (see Klonsky, 2007) and drawing on discussions with researchers and treatment professionals, as well as websites designed by and for self-injurers (Klonsky & Glenn, 2009). The specific functions assessed by the ISAS include seeking sensations; gaining autonomy; masking distress; setting interpersonal boundaries; enhancing interpersonal efficacy, peer bonding, and self-care; affecting self-punishment, revenge, and toughness; and regulating affect, dissociation, suicidal thoughts, feelings, and impulses.

The ISAS also includes five questions that elicit descriptive and contextual information regarding individuals’ NSSI behaviors. Specifically, the ISAS contains items regarding the age of onset of NSSI, NSSI-induced pain, and the enactment of NSSI alone or in the presence of others. The ISAS also includes items that ask about the duration of NSSI urges (e.g., the time between the urge to engage in NSSI and the act of NSSI) and the desire to stop self-injuring. The FASM (Lloyd et al., 1998; Nock & Prinstein, 2004, 2005) has also been developed to measure self-injury. However, the FASM fails to explore several functions, such as sensation-seeking, coping with suicidal thoughts, and setting interpersonal boundaries (Klonsky, 2007; Klonsky & Weinberg, 2009).

SITBI

Another tool commonly used to measure NSSI is the SITBI (Nock, Homberg, Photos, & Michel, 2007), which has been originally developed as a comprehensive tool for the measurement of self-injury by both researchers and clinicians. Unlike other instruments, the SITBI is a brief interview schedule used to capture information on the presence, frequency, and characteristics of NSSI, as well as suicidal ideation, plans, gestures, and attempts. Germane to NSSI, the subject characteristics captured by the SITBI include the age of onset, methods, severity, functions, precipitants, pain inducement, the use of alcohol and drugs during episodes, impulsiveness, peer influences, and future likelihood of each type of NSSI (Nock, Homberg, Photos, & Michel, 2007).

Reasons for NSSI

Self-injurers have intrapersonal or interpersonal vulnerabilities that limit their ability to respond adaptively to challenging and stressful events. Therefore, they may employ self-injury or other dysfunctional behaviors as coping mechanisms to regulate their affective, cognitive, or social experiences (Nock & Menes, 2008). For example, engagers in NSSI demonstrate intrapersonal difficulties with affect regulation, such as higher levels of physiological arousal in response to frustrating tasks (Nock & Menes, 2008) or stressful events (Nock, Wedig, Janis, & Deliberto, 2008). Adolescents who experience higher levels of psychological distress in response to stressful situations, and are less capable of tolerating distress, are at a higher risk of NSSI (Anestis, Knorr, Tull, Lavender, & Gratz, 2013; Najmi, Wegner, & Nock, 2007). Individuals who engage in self-injury have also been found to struggle with aversive thoughts and feelings (Najmi, Wegner, & Nock, 2007) and possess less ability to tolerate distress (Nock & Menes, 2008). Therefore, people who undergo higher levels of psychological distress may employ self-injurious behaviors as a coping mechanism in adolescence (Baetens et al., 2014), as well as in younger (Klonsky, 2009) and older (Briere & Gil, 1998) adulthood.

Studies have attempted to provide a better understanding of the purposes of self-injury, and several explanations have been proposed. For example, research has indicated that self-injury is meant to demonstrate control over urges concerning sex or death (Cross, 1993), to define boundaries between the self and others (Suyemoto, 1998), to end dissociative episodes (Herpertz, 1995), or to protect others from personal anger or rage (Suyemoto, 1998). Therefore, NSSI appears to serve both intrapersonal and interpersonal functions. The former is self-focused (e.g., affect regulation and self-punishment), while the latter is other-focused, encompassing purposes such as peer bonding (e.g., fitting in with others) and interpersonal influence (e.g., letting others know the extent of emotional pain) (Klonsky, Victor, & Saffer, 2014).

Those who engage in NSSI may do so to escape distressing thoughts or emotions by distracting them with physical pain (Hornor, 2016). In addition, NSSI releases endogenous opiates in response to tissue damage, which can produce euphoria (Selby, Bender, Gordon, Nock, & Joiner, 2012). NSSI can also help facilitate emotional regulation through self-punishment (e.g., the self-punishment model) (Klonsky, 2007, pp. 229–230). Finally, NSSI can provide relief by assuaging negative emotions (e.g., guilt) and inducing a more positive emotional state (e.g., relief).

The defective self-model of NSSI (Hooley & Germain, 2014; Hooley, Ho, Slater, & Lockshin, 2010) suggested that the pain of self-injury yields emotional benefits in self-critical individuals who feel deserving of physical pain. For others, engaging in NSSI may elicit feelings of numbness or emptiness (Peterson, Freedenthal, Sheldon, & Andersen, 2008). In other words, those who engage in NSSI may want to feel something, even if that feeling is physical pain (Penn, Esposito, Schaeffer, Fritz, & Spirito, 2003). Interestingly, others have reported that engaging in NSSI elicits positive emotions, such as fun and excitement (Laye-Gindhu & Schonert-Reichl, 2005).

Self-injury can serve as a maladaptive short-term coping mechanism (Favazza, 1998; Whitlock, 2010). The most common reasons for NSSI, endorsed by at least 50% of community survey participants, included feelings of depression, loneliness, low self-esteem, hopelessness, self-loathing, and emotional pain, as well as the need to self-injure, self-punish, and signal emotional distress (Gluck, 2012; Laye-Gindhu & Schonert-Reichl, 2005). These studies have also revealed gender differences in the reported motivations for engaging in NSSI. Men who engaged in self-injury were more likely than women to report reasons such as combatting boredom, wanting to join a group, thinking self-injury would be enjoyable, and using self-injury to avoid unpleasant activities. Meanwhile, women were more likely than men to report feeling very unhappy or depressed and needing to hurt themselves as motivations for self-injury (Laye-Gindhu & Schonert-Reichl, 2005).

Other reasons for engaging in self-injury include alleviating anxiety and other painful thoughts or feelings (i.e., affect regulation), ending episodes of depersonalization, and attaining a sense of security or uniqueness. Furthermore, NSSI can serve as a mechanism for communicating emotional needs, reenacting trauma, reestablishing self-control, expressing gender or sexual orientation struggles, responding to states of under-arousal or over-arousal to stress, reducing tension, influencing others, and self-stimulation (Favazza, 2011, 2012; Hawton, Saunders, & O’Conner, 2012; Whitlock, 2010).

Cultural infections on NSSI

The stereotypic self-injurer is a White, middle-class, female adolescent or young woman. However, while this demographic group does exhibit high rates of self-injury, the belief that NSSI is exclusively a “rich White girl problem” is inaccurate (Shaw, 2002). Self-injury transcends race and economic boundaries (DeAngelis, 2015), and it should be understood not only as a psychiatric symptom but also as an expression of distress linked to feelings of “marginalization and injustice” (McAllister, 2003, p. 182). Examining this perspective further, cultural explorations of NSSI have suggested that the act of self-harm turns the body into a canvas that can be interpreted through a social lens rather than solely through the narrow perspective of individual experiences or psychodynamics (McAllister, 2003).

Culture is intrinsic to understandings of self-harm (Favazza, 1996). For example, in various religious and other cultural practices, self-mutilation is a sanctioned rite of passage that is purported to foster wisdom, enhance self-knowledge, promote healing of the self and others, and engender a sense of power and control (self-efficacy). Such a conception of NSSI moves it beyond the realm of individual psychopathology and imbues it with significant social purpose and cultural meaning. People who self-injure have been categorized into “culturally sanctioned” and “deviant” groups. The distinction between acceptable and non-acceptable self-injury is based on the notion that “deviant” NSSI is a “product of mental disorder or anguish,” whereas “sanctioned” NSSI originates from broader social meanings or practices (Favazza, 1996, p. xix).

NSSI has also been considered from the standpoint of psychological and social oppression, which is consistent with the characteristics of self-injury and predicts that marginalized people are more likely to self-injure (LaGuardia-LoBianco, 2019). The NSSI model of oppression can be applied to a variety of individuals from different racial, class, and ethnic groups who engage in self-injurious behavior, including women and girls. Within this framework, NSSI is a way of “[alleviating] feelings of self-hatred, mitigating dissociation, and seeking to regain control” (LaGuardia-LoBianco, 2019, p. 297). By linking the features of oppression and NSSI, a cultural framework can be constructed to elucidate NSSI across marginalized groups (LaGuardia-LoBianco, 2019). For example, for individuals who are systemically disempowered, NSSI can serve as an expression of agency by encouraging the oppressed to reclaim ownership over their own bodies or emotions and reestablish a sense of control or authority over their lives (LaGuardia-LoBianco, 2019).

Sociocultural explanations have been proposed to shed light on the prevalence of NSSI among White girls and women, often rooted in the impact of oppressive socialization, particularly the influence of Western standards of beauty (Bresin & Schoenleber, 2015; Shaw, 2002; Smith, Cox, & Saradjian, 1999). For them, self-injury serves as a means to both reenact and resist the culturally pervasive bodily objectification and violations they experience (Shaw, 2002). From a feminist ideology, NSSI among White women is a hard reality and a shocking reflection of their oppression, contributing to the severe social scrutiny of self-injury (LaGuardia-LoBianco, 2019). In short, NSSI is “a symptom of a larger relational crisis for girls and women in western culture” (Shaw, 2002, p. 202).

There is a notable contradiction in societal attitudes toward NSSI when compared to self-directed harm for the purpose of aesthetic enhancement (waist training, hair removal, filler injections, etc.), which is often encouraged and even celebrated. Western culture readily condones violence to the female body for beautification purposes (LaGuardia-LoBianco, 2019). In contrast, NSSI undertaken for managing distress can lead to visible scars, leaving the skin “ugly,” and is considered an unacceptable and stigmatizing behavior. However, from a cultural viewpoint, NSSI can be construed as a mechanism for taking control of bodies that are socially claimed by others (Shaw, 2002).

Mental health disorders and self-injury

The presence of a psychiatric disorder fails to fully explain why people self-injure (Nock, 2009b). Although NSSI and suicidal behavior are distinct and “actually counter-intentional” (Ross & McKay, 1979, p. 4), those who self-injure are significantly more likely to express suicidal ideation and to plan and attempt suicide than those who do not self-injure (Brent, 2011). For example, in one study, between 25% and 67% of those aged 13 to 24 who had died by suicide had a history of NSSI (Nock, 2009b). Other researchers have observed that NSSI affords people with an “acquired capability” for suicide and habituates them to the pain of self-injury (Van Orden, Witte, Gordon, Bender, & Joiner, 2008). Nonetheless, some “studies find that self-injury is often undertaken as a means of avoiding suicide” (Caicedo & Whitlock, 2009, p. 1).

Studies have revealed that between 15% and 20% of adolescents who engage in NSSI have a diagnosable psychiatric illness (Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006). In clinical populations, self-injury can co-occur with several mental health disorders, such as posttraumatic stress, mood, anxiety, substance use, eating, impulse control, dissociative, and personality disorders, more specifically borderline personality disorder (BPD) (Briere & Gil, 1998; Glenn & Klonsky, 2013; Gluck, 2012; Vaughn, Salas-Wright, Underwood, & Gochez-Kerr, 2015; Whitlock, 2010). In addition, self-injury is more common among adolescents and young adults who identify as bisexual or transgender than among those who do not identify as such (Sornberger, Smith, Toste, & Heath, 2013; Whitlock, 2010). However, it is important to note that not all marginalized groups based on sexual identities self-injure, and not all those that self-injure have a mental health disorder.

NSSI and DSM-5

The recognition of NSSI as distinct from other mental health disorders has led to its inclusion as a distinguishable diagnosis in the DSM, Fifth Edition (DSM-5; American Psychiatric Association [APA], 2013). Previous editions of the DSM included NSSI only as a symptom of BPD and not as a distinct diagnosis (APA, 1994).

In the DSM-5, the diagnostic criteria for NSSI disorder includes intentional self-injury without suicidal intent for five or more days in the past year. Such behaviors must be performed with the expectation of obtaining relief from a negative feeling or cognitive state, resolving an interpersonal difficulty, or inducing a positive affective state (APA, 2013). Moreover, self-injurious behaviors must be associated with at least one of the following criteria: interpersonal difficulties or negative thoughts or feelings immediately preceding the behavior, premeditation prior to self-injury (e.g., planning self-injury), or a preoccupation with self-injury (e.g., frequent or repetitive thoughts about NSSI) (APA, 2013).

The self-injurious behaviors must also be serious enough to cause clinically significant distress or interfere with critical areas of functioning. In addition, the self-injurious behaviors must not be socially sanctioned (e.g., body piercing, tattooing, or part of a cultural or religious ritual) or occur exclusively during psychosis, delirium, or substance intoxication or withdrawal. Most individuals who self-injure report a level of daily functioning comparable to that of their counterparts that do not self-injure. Thus, people who self-injure fail to meet the diagnostic criteria for an NSSI disorder, including those with a single episode of self-injury. For example, one study showed that 55% of a community sample of adolescents have reported engaging in some form of NSSI (Lloyd-Richardson, Perrine, Dierker, & Kelley, 2007). Within this sample, 28% have engaged in only “moderate” forms of NSSI (e.g., self-cutting or burning), and less than 5% have engaged in NSSI on more than five occasions. Similar trends have been found among samples of Chinese adolescents (Tang et al., 2013). The designation of five or more occurrences of NSSI is based on the notion that repeated incidents of NSSI indicate evidence of a clinically significant pattern. Others have suggested that the requisite five occurrences may be too low “to meaningfully differentiate between clinical and subclinical groups who engage in NSSI” (Hooley, Fox, & Boccagno, 2020, p. 105).

Investigations have suggested that NSSI can become a distinct diagnostic category, which has led to the inclusion of the NSSI disorder in the DSM-5 section for conditions for future study (APA, 2013). However, limited research has examined the validity of Criterion A (the frequency criterion). In DSM-5-TR, free‐standing symptom codes have been added to the chapter “Other Conditions That May Be a Focus of Clinical Attention” to indicate the presence or history of suicidal behavior (“potentially self‐injurious behavior with at least some intent to die”) and nonsuicidal self‐injury (“intentional self‐inflicted damage to the body likely to induce bleeding, bruising, or pain in the absence of suicidal intent”). These codes would allow clinicians to record clinically important behaviors independent of any psychiatric diagnosis (APA, 2022).

NSSI and BPD

A broad range of dysfunctional behaviors and psychiatric diagnoses are associated with NSSI (Vaughn, Salas-Wright, Underwood, & Gochez-Kerr, 2015). In fact, NSSI falls under Criterion 5 for the diagnosis of BPD (APA, 2013; Selby, Bender, Gordon, Nock, & Joiner, 2012). Nonetheless, NSSI can be identified among individuals without BPD or any other diagnosable mental health disorder (Hornor, 2016). NSSI has been viewed historically as a symptom of BPD (Klonsky, Victor, & Saffer, 2014). For example, the single appearance of NSSI in the DSM-IV (APA, 1994) was considered a symptom of BPD. While NSSI has been associated with several mental health related issues and psychiatric conditions (e.g., Andover, Pepper, Ryabchenko, Orrico, & Gibb, 2005; Klonsky & Muehlenkamp, 2007; Klonsky, Oltmanns, & Turkheimer, 2003; Nock, Wedig, Janis, & Deliberto, 2008; Ose, Tveit, & Mehlum, 2021; Wang, Liu, Yang, & Zou, 2021), it appears to be uniquely and strongly associated with BPD (Andover, Pepper, Ryabchenko, Orrico, & Gibb, 2005; Linehan, 1993). Among female adolescents with histories of NSSI, 52% met the diagnostic criteria for BPD (Nock, Joiner, Gordon, Lloyd-Richardson, & Prinstein, 2006). Other studies have indicated that the rates of NSSI among individuals with BPD can be as high as 65% to 80% (Glenn & Klonsky, 2013; Soloff, Lis, Kelly, Cornelius, & Ulrich, 1994). More recent research has demonstrated that NSSI is related to BPD but also that engagers in NSSI may have no other symptoms of BPD (Levine, Aljabari, Dalrymple, & Zimmerman, 2020).

As described by the APA, 2013), BPD is a serious mental health disorder characterized by affect dysregulation, self-injury, and instability in self-image and interpersonal relationships. As the core dimensions of the disorder, research has suggested a three-factor model of BPD consisting of behavioral dysregulation, disturbed relatedness, and emotional dysregulation (e.g., Brickman, Ammerman, Look, Berman, & McCloskey, 2014). The first factor, behavioral dysregulation, pertains to self-injury (e.g., NSSI), suicidal behaviors, and impulsivity, whereas disturbed relatedness refers to a distorted sense of self and relationships with others (Brickman, Ammerman, Look, Berman, & McCloskey, 2014). Approximately 2% to 6% of the general population (Grant et al., 2008; Lieb, Zanarini, Schmahl, Linehan, & Bohus, 2004), 11% of outpatient populations, and 19% of inpatient populations (Black, Blum, Pfohl, & Hale, 2004) are affected by BPD.

As in other diagnostic groups, people with BPD who engage in NSSI do so for various reasons, including to release tension, alleviate negative emotions, and self-punish (Kleindienst et al., 2008). Notably, among individuals with BPD, NSSI more often serves intrapersonal functions (e.g., regulating emotions and self-punishing) than interpersonal functions (e.g., bonding with peers or establishing autonomy) (Sadeh et al., 2014; Vega et al., 2017). Comparisons between self-injury behaviors in those individuals with BPD and those without BPD have shown that the former endorses interpersonal influence and self-care functions more frequently (Vega et al., 2017).

The use of NSSI to serve intrapersonal functions or alter internal states (e.g., thoughts or emotions) among people with BPD is expected because emotional dysregulation is a critical feature of BPD. Compared with other clinical groups, individuals with BPD may be more inclined to engage in NSSI as a way of managing emotions rather than for other functions. However, BPD symptoms have been found to parallel those of NSSI disorder. Specifically, BPD symptoms relating to affect dysregulation are associated with the intrapersonal functions of NSSI, and BPD symptoms relating to interpersonal conflict are associated with the interpersonal functions of NSSI (Sadeh et al., 2014). Hence, clusters of BPD symptoms may have unique relationships with the functions of NSSI (Sadeh et al., 2014).

The presentation of NSSI in the context of BPD may differ from that found among other disorders. Although the age of onset appears to be similar across clinical groups (Vega et al., 2017), individuals who self-injure with BPD have been found to engage in NSSI more frequently, use a greater variety of self-injurious methods, and enact more severe forms of NSSI, such as burning and swallowing dangerous substances (Vega et al., 2017, see also Jacobson et al., 2008; Sadeh et al., 2014; Turner et al., 2015).

Recommendations for clinical practice

For clinical social workers and other behavioral health care providers, the findings of this review suggest several core components of identifying and treating patients who engage in NSSI. These components include self-reflection among providers, integrated assessment protocols, and comprehensive treatment plans. Self-reflection among health care practitioners is the first step in establishing a therapeutic process. It involves regularly updating their knowledge of NSSI-related issues, such as principal symptoms, signs, and other clinical characteristics; typical sites and methods of self-injury; and co-occurring conditions and behaviors that are precursors and sequelae of self-injury (Gratz, Dixon-Gordon, Chapman, & Tull, 2015; Mathew et al., 2020; Singhal, Bhola, Reddi, Bhaskarapillai, & Joseph, 2021). Additionally, fostering more empathetic patient care and deriving optimal patient outcomes require clinicians to openly recognize negative personal perceptions or biases regarding NSSI (Ngune et al., 2021).

The next step in NSSI patient care is a holistic evaluation that entails physical examination, mental health assessment, and other relevant screenings to gather further information on related patient conditions as well as social and substance use histories. Physical examination primarily requires evaluating the pattern and severity of self-harm injury (Burke, Hamilton, Cohen, Stange, & Alloy, 2016; Singhal, Bhola, Reddi, Bhaskarapillai, & Joseph, 2021), while mental health evaluation involves essential tasks that include mental status examination, psychiatric history derivation, and psychosocial needs assessment. Examining mental status and documenting psychiatric history can ascertain subsequent risks of suicide and co-occurring mental health conditions, such as anxiety and mood disorders (Burke, Hamilton, Cohen, Stange, & Alloy, 2016; Mathew et al., 2020). Finally, psychosocial needs assessment explores alcohol and other substance use disorders, which are often correlated with NSSI (Gratz, Dixon-Gordon, Chapman, & Tull, 2015; Young, Simonton, Key, Barczyk, & Lawson, 2017). It is also important to consider additional risk factors for NSSI, including BPD, gender, age, ethnicity, race, gender dysphoria, and previous trauma or abuse.

No single instrument can comprehensively evaluate all the factors necessary for the clinical assessment of NSSI (Faura-Garcia, Orue, & Calvete, 2020), but the basic conditions associated with it can be assessed using screening tools (e.g., SITBI and ISAS). Clinicians must determine which of these tools will be most beneficial during assessment on the basis of patients’ reports and clinical presentations. Throughout the assessment and screening processes, the integration of findings is especially crucial when a patient is positive for suicide risk (e.g., the Columbia-Suicide Severity Rating Scale) (Oquendo, Halberstam, & Mann, 2003).

Clinicians should also explore a variety of treatment options for individuals engaging in NSSI. The first order of treatment is to attend to acute injury. Serious injuries can warrant a visit to a medical facility with a subsequent psychiatric assessment of suicide risk, inpatient follow-up care and treatment, and appropriate referrals as necessary, including participation in partial hospitalization and other outpatient programs. Long-term treatment is recommended in cases of co-occurring mental health disorders, such as BPD. A central focus of treatment for patients who engage in NSSI is addressing their dysfunctional emotional coping mechanisms (Young, Simonton, Key, Barczyk, & Lawson, 2017). This approach includes focusing on “emotions, trauma, relationship quality, sense of loss, and risky behaviors” that are related or contribute to engagement in NSSI (Young, Simonton, Key, Barczyk, & Lawson, 2017, p. 339). Early screening and intervention are factors for reducing the enduring impact of NSSI (Young, Simonton, Key, Barczyk, & Lawson, 2017).

Conclusion

NSSI has been a central element of cultural, spiritual, and healing rituals throughout history. In recent years, the incidence of this practice in Western cultures has increased, specifically among adolescent and young adult populations. Clinicians must understand the key components and terminologies of NSSI and related mental health disorders. Comprehensive assessment and treatment planning options are needed to provide more effective and holistic care to NSSI patients.

In conclusion, NSSI is a complex behavior with numerous causes and manifestations that vary in terms of onset, frequency, modes of expression, and severity. Self-injury is rarely an isolated or stand-alone condition and has not been identified as a singular diagnostic entity in DSM-5-TR. However, NSSI is a diagnostic criterion of BPD and as such BPD might provide some general guidelines for the treatment NSSI, which can also accompany other clinical conditions beyond BPD. Although the exact cause of NSSI is unknown, it tends to emerge in adolescence and early adulthood and likely stems from a combination of genetic and environmental causes, such as childhood abuse and trauma. The best path forward for mental health providers is to employ eclectic but targeted interventions that include manualized psychotherapeutic techniques, use of hospitalization and medication as needed, and the inculcation of coping skills to equip patients with immediate and lasting alternatives to self-injury.

Disclosure statement

No potential conflict of interest was reported by the author(s).