Self-injury has been defined by the International Society for the Study of Self-Injury as the deliberate, self-inflicted destruction of body tissue without suicidal intent and for purposes not socially sanctioned. It is also sometimes referred to as non-suicidal self-injury, self-injurious behavior, or deliberate self-harm.
Although cutting is one of the most well-known self-injury behaviors, it can take many forms ranging from cutting or burning to self-bruising or breaking bones. Hands, wrists, stomach, and thighs are commonly affected areas, though self-injury can happen anywhere on the body. The severity of self-injury can range from superficial wounds to lasting scars or disfigurement.
Research with secondary school and young adult populations have generally found 12% to 24% of young people have self-injured, with one study finding 47% of adolescents had engaged in some form of NSSI in the past year. Most studies find 6-8% of adolescents and young adults reporting current, chronic self-injury. Self-injury typically begins in mid-adolescence, with studies finding the average age of onset to range from 12 to 15 years of age. For many, self-injury is a maladaptive coping method that is periodically relied upon for a period of months or years, though for some it is used well into adulthood.
While still not definitive, research suggests that self-injury is only slightly more common in females than it is in males. There is evidence that the forms used differ between males and females, with females more like to use better recognized forms such as cutting or scratching and males more like to use forms that result in bruising, such as self-battery or engaging in fighting with the intention of hurting themselves.
Self-injury is primarily used as a maladaptive coping method. When faced with situations that evoke strong and overwhelming emotions such as sadness, anxiety, anger, or even emotional numbness, self-injury is used to manage or reduce these feelings. Many also report that they experience self-injury as an expression of self-directed anger or punishment. For some, self-injury is also socially reinforced, such as when others pay more (or less) attention to an individual following an act of self-injury.
The relationship between self-injury and suicide is complex. While most acts of self-injury are not accompanied by suicidal thoughts, evidence suggests those who have self-injured are more likely to attempt suicide than those who have never self-injured. Importantly, engaging in NSSI is associated with two important risk-factors for suicide: 1) the experience of emotional distress, and 2) experience inflicting pain and injury on oneself. In short, although NSSI is not a suicide attempt, the presence of NSSI does increase the likelihood that someone may consider or attempt suicide, and NSSI should be considered as an important risk-factor for suicide.
NSSI in DSM-5
The American Psychiatric Association has added Non-Suicidal Self-Injury as a research diagnosis in the 5th revision of the Diagnostic and Statistical Manual for Psychiatric Disorders (DSM). Dr. David Shaffer at Columbia University led the task force that developed proposal. ISSS was consulted on the development of the criteria, and several ISSS members served as consultants. Unfortunately, NSSI has not been included in the current revision of the DSM; however, research is ongoing to improve the reliability and validity of a NSSI diagnosis.