Nonsuicidal self-injury (NSSI) involves deliberate damage to body tissue such as might occur with skin cutting or burning (Nock, 2009 ). This behavior (which is sometimes called self-mutilation) occurs in the absence of an intent to die (hence the term nonsuicidal). Self-mutilating behavior has long been listed in the DSM as a symptom of BPD. However, many people who engage in self-injury do not have BPD, although they do report high levels of depressive symptoms, anxiety, suicidality, and generally low levels of functioning (Selby et al., 2012 ). People who engage in NSSI are also at elevated risk for later suicide (Wilkinson et al., 2011 ). For these reasons, the DSM-5 task force was charged with determining whether people who display a significant amount of nonsuicidal self-injurious behavior should be diagnosed with a new disorder that would called “nonsuicidal self-injury disorder”.
NSSI is found in males and females, as well as in people of all ethnicities and economic backgrounds. However, the risk for NSSI seems to be greatest in the adolescent years. One Finnish study reported a 11.5 percent prevalence rate in young people aged 13–18. And an Internet-based study of college students at two U.S. universities found a lifetime prevalence of 17 percent. Perhaps most shocking were the results from a U.S. study of 10-to 14-year-old girls that found a lifetime prevalence of NSSI of 56 percent (Hilt et al., 2008 ).
Why do people hurt themselves by cutting or burning? Tension relief is one reason that many people give. NSSI is often used to regulate intense or extreme emotions. Hooley et al. ( 2010 ) have also found that people who engage in NSSI tend to have higher pain endurances than the rest of us. In addition, they have a highly self-critical cognitive style and “may regard suffering and pain as something they deserve” (Hooley et al., 2010 , p. 170). This may help explain why such people choose to regulate their emotions by engaging in behaviors that are self-damaging and painful.
NSSI is a growing problem. Recognizing this, it has now been added to DSM-5. NSSI disorder is listed in Section III, which is used to describe conditions in need of further study. This move is likely to stimulate research. As we learn more we may be in a better position to understand, treat, and perhaps even prevent this increasingly prevalent condition.
In addition to affective and impulsive behavioral symptoms, as many as 75 percent of people with BPD have cognitive symptoms. These include relatively short or transient episodes in which they appear to be out of contact with reality and experience delusions or other psychotic-like symptoms such as hallucinations, paranoid ideas, or severe dissociative symptoms (Lieb et al., 2004 ; Paris, 2007 ; Skodol, Gunderson et al., 2002 ).
Estimates are that only about 1 to 2 percent of the population may qualify for the diagnosis of BPD (Lenzenweger et al., 2007 ), but they represent about 10 percent of patients in outpatient and 20 percent of patients in inpatient clinical settings (Lieb et al., 2004 ; Torgersen et al., 2001 ). Although early research found that approximately 75 percent of individuals receiving this diagnosis in clinical settings are women, such findings likely arise from a gender imbalance in treatment seeking rather than prevalence of the disorder. In support of this, more recent epidemiological studies of community residents suggest an equal gender ratio (Coid et al., 2009 ; Grant et al., 2008 ; Hooley et al., 2012 ).