Examining Nock and Prinstein’s four-function model with offenders who self-injure.

Nonsuicidal self-injury (NSSI) is the deliberate bodily harm or disfigurement without suicidal intent and for purposes not socially sanctioned (e.g., cutting, burning, head banging). Nock and Prinstein (2004) proposed a 4-function model (FFM) of NSSI, in which the functions of NSSI are categorized by two dichotomous factors: (a) positive (i.e., involves the addition of a favorable stimulus) or negative (i.e., involves the removal of an aversive stimulus; and (b) automatic (i.e., intrapersonal) or social (i.e., interpersonal). This study examined the validity of this model with incarcerated populations. In-depth semistructured interviews with 201 incarcerated offenders were analyzed and categorized based on the FFM. Participants' descriptions of functions of NSSI were most commonly categorized as automatic negative reinforcement (25.0%; e.g., coping with negative emotions), followed by automatic positive reinforcement (31.3%; e.g., self-punishment), social positive reinforcement (31.3%; e.g., to communicate with others), and social negative reinforcement (12.5%; e.g., to avoid hurting someone else). While the uniqueness of the correctional environment affects some of the specific functions evident in offenders, FFM can be used to adequately organize the functions of NSSI in offenders, providing a useful tool for explaining this complex behavior. Clinically, NSSI in offenders can be viewed has having the same underlying motivations, although automatic positive reinforcement is more prevalent in offenders and social positive reinforcement is more prevalence in nonoffenders. Given that the motivations underlying nonsuicidal self-injury are similar for offender and nonoffender populations, similar treatment approaches may be effective with both populations. (PsycINFO Database Record