Two theories of psychopathology—based on functional behavioral analyses—have been proposed: In the first, based on learning theory, either positive or negative reinforcement sustains the behavior. Positive reinforcement might result from punishing oneself in a way that the individual feels is deserved, with the behavior inducing a pleasant and relaxed state or generating attention and help from a significant other, or as an expression of anger. Neg- ative reinforcement results from affect regulation and the reduction of unpleasant emotions or avoiding distressing thoughts, including thinking about suicide. In the second theory, nonsuicidal self-injury is thought to be a form of self—punishment, in which self—punitive ac- tions are engaged in to make up for acts that caused distress or harm to others.
Functional Consequences of Nonsuicidal SeIf-lniury
The act of cuttingkmight be performed with shared implements, raising the possibility of blood—bome disease transmission.
Borderline personality disorder. As indicated, nonsuicidal self-injury has long been re- garded as a ”symptom" of borderline personality disorder, even though comprehensive clinical evaluations have found that most individuals with nonsuicidal self-injury have symptoms that also meet criteria for other diagnoses, with eating disorders and substance use disorders being especially common. Historically, nonsuicidal self-injury was regarded as pathognomonic of borderline personality disorder. Both conditions are associated with several other diagnoses. Although frequently associated, borderline personality disorder is not invariably found in individuals with nonsuicidal self—injury. The two conditions dif- fer in several ways. Individuals with borderline personality disorder often manifest dis- turbed aggressive and hostile behaviors, whereas nonsuicidal self—injury is more often associated with phases of closeness, collaborative behaviors, and positive relationships. At a more fundamental level, there are differences in the involvement of different neurotrans— mitter systems, but these will not be apparent on clinical examination.
Suicidal behavior disorder. The differentiation between nonsuicidal self-injury and sui- cidal behavior disorder is based either on the stated goal of the behavior being a wish to die (suicidal behavior disorder) or, in nonsuicidal self—injury, to experience relief as de- scribed in the criteria. Depending on the circumstances, individuals may provide reports of convenience, and several studies report high rates of false intent declaration. Individu- als with a history of frequent nonsuicidal self—injury episodes have learned that a session of cutting, while painful, is, in the short-term, largely benign. Because individuals with nonsuicidal self—injury can and do attempt and commit suicide, it is important to check past history of suicidal behavior and to obtain information from a third party concerning any recent change in stress exposure and mood. Likelihood of suicide intent has been as- sociated with the use of multiple previous methods of self—harm.
In a follow-up study of cases of ”self—harm" in males treated at one of several multiple emergency centers in the United Kingdom, individuals with nonsuicidal self-injury were significantly more likely to commit suicide than other teenage individuals drawn from the same cohort. Studies that have examined the relationship between nonsuicidal self-injury and suicidal behavior disorder are limited by being retrospective and failing to obtain ver- ified accounts of the method used during previous "attempts.” A significant proportion of have ever engaged in self-cutting (or their preferred means of self—injury) with an intention to die. It is reasonable to conclude that nonsuicidal self-injury, while not presenting a high risk for suicide when first manifested, is an especially dangerous form of self—injurious behavior.
This conclusion is also supported by a multisite study of depressed adolescents who had previously failed to respond to antidepressant medication, which noted that those with pre- vious nonsuicidal self—injury did not respond to cognitive-behavioral therapy, and by a study that found that nonsuicidal self-injury is a predictor of substance use/misuse.