Examining the link between nonsuicidal self-injury and suicidal behavior: a review of the literature and an integrated model.

Self-injurious behaviors (SIB) refer to behaviors that cause direct and deliberate harm to oneself, including nonsuicidal self-injury (NSSI), suicidal behaviors, and suicide. Although in recent research, NSSI and suicidal behavior have been differentiated by intention, frequency, and lethality of behavior, researchers have also shown that these two types of self-injurious behavior often co-occur. Despite the co-occurrence of NSSI and suicidal behavior, however, little attention has been given as to why these self-injurious behaviors may be linked. Several authors have suggested that NSSI is a risk factor for suicidal behavior, but no comprehensive review of the literature on NSSI and suicidal behavior has been provided. To address this gap in the literature, we conducted an extensive review of the research on NSSI and suicidal behavior among adolescents and adults. First, we summarize several studies that specifically examined the association between NSSI and suicidal behavior. Next, three theories that have been proposed to account for the link between NSSI and suicidal behavior are described, and the empirical support for each theory is critically examined. Finally, an integrated model is introduced and several recommendations for future research are provided to extend theory development.