Nonsuicidal Self-Injury: What We Know, and What We Need to Know

For decades, knowledge about nonsuicidal self-injury (NSSI) was limited to only a small handful of empirical studies. However, the last 10 to 15 years have witnessed an explosion of research and significant advances in knowledge about NSSI. We now understand much about the classification, prevalence, correlates, forms, and functions of NSSI, and have dispelled many misconceptions. It is time for NSSI researchers to apply tills basic knowledge to develop empirically grounded theoretical models and effective treatments. Tills In Review on NSSI was developed to help the field of mental health move forward in these 2 areas. First, tills editorial briefly reviews what we now know about NSSI. Next, Margaret S Andover and Blair W Morris1 describe an emotion regulation model for understanding and potentially treating NSSI and for explaining the emotion regulation function of NSSI in terms of basic emotion models. Finally, Brianna J Turner, Sara B Austin, and Alexander L Chapman2 provide a systematic review of NSSI treatment outcome research, and note the need for new treatment approaches specifically tailored to targetNSSI. We hope that tills In Review not only provides state-of-the-art knowledge but also motivates and facilitates future efforts to better understand and treat NSSI.NSSI refers to the intentional destmction of one's own body tissue without suicidal intent and for purposes not socially sanctioned.3 4 Coimnon examples include cutting, burning, scratching, and banging or hitting, and most people who self-injure have used multiple methods.3 Because NSSI is typically associated with emotional and psychiatric distress,5,6 and because NSSI increases risk for suicide,7,8 it is cmcial to establish accurate conceptual and clinical models of tills behaviour. In tills introduction to the In Review on NSSI, we summarize what is now known about NSSI (much of which lias been learned in just the past 10 to 15 years), dispel common myths, and describe the 2 review articles featured in tills special section.What We Now KnowDespite some notable exceptions,9-11 few researchers focused attention on NSSI until recently. One might identify the early 2000s as a turning point. Kim L Gratz12 published an influential measure that facilitated research on NSSI, E David Klonsky and colleagues5 found that NSSI is present and associated with psychiatric morbidity even in nonclinical populations, Matthew K Nock and Mitch J Prinstein13 drew attention to the reasons why people engage in NSSI, and Jennifer J Muehlenkamp (see Muehlenkamp14 and Muehlenkamp and Gutierrez15) argued that NSSI should be distinguished from other SIBs, such as attempted suicide, and regarded as an independent clinical syndrome. Each of these publications has been cited in hundreds of subsequent articles, and together they arguably provided a foundation for subsequent work that has answered many key questions about the nature of NSSI, including who self-injures, why people self-injure, and the complex relation between NSSI and suicidal behaviour.Who Self-injures? NSSI is most common among adolescents and young adults. Lifetime rates in these populations are about 15% to 20%,16,17 and onset typically occurs around age 13 or 14.6,18 In contrast, about 6% of adults report a history of NSSI.19,20 It is unclear whether the lower lifetime rate in adults reflects an increase in NSSI among recent cohorts of adolescents or an artifact of memory by which most adults who self- injured as adolescents do not recall their NSSI. Generally speaking, rates of NSSI appear to be similar across different countries.21In both adolescents and adults, rates of NSSI are highest among psychiatric populations, particularly people who report characteristics associated with emotional distress, such as negative emotionality, depression, anxiety, and emotion dysregulation.5,18,22,23 NSSI is especially common in people prone to self-directed negative emotions and self-criticism. …