The association between nonsuicidal and suicidal self-injurious behaviors: A systematic review and expanded...

Nonsuicidal self-injury (NSSI) is one of the strongest predictors of suicidal behavior. Despite this, the field still has a limited understanding of the mechanisms by which this relationship is conferred.

We conducted a systematic review of the empirical research examining potential factors driving (i.e., moderators, mediators) the relationship between NSSI and suicidal behavior to address this gap in the literature.

We identified only 15 studies examining moderators or mediators of this relationship, examining 40 unique mediators and 22 unique moderators. Three prominent weaknesses were identified in the reviewed literature: (1) limited intersection with existing theoretical models of the NSSI - suicidal behavior relationship, (2) little replication of findings across studies (i.e., only four mediators and four moderators assessed in multiple studies), and (3) only one of the included studies utilized a prospective design. Research to date does little to improve our understanding of the theoretical or prospective relationship between NSSI and suicidal behavior, highlighting a foundational gap in the literature.

We propose the Nonsuicidal to Suicidal Self-Injury Pathway Model, a new conceptual model of the relationship between NSSI and suicidal behavior, drawing on extant theory and empirical research; we discuss future directions for work in this area.