Implicit cognition about self-injury predicts actual self-injurious behavior: results from a longitudinal study of adolescents

Background: The implicit association hypothesis of nonsuicidal self-injury (NSSI) proposes that individuals who engage in self-injury develop, over time, strong associations between themselves and NSSI, and their identification with this behavior guides their future selection of NSSI to cope. Prior research has established a relationship between implicit NSSI associations (using an Implicit Association Test for Self-Injury) and engagement in NSSI. However, previous studies have been small and cross-sectional, and thus underpowered to examine the nature of this association and the extent to which implicit associations predict the persistence of NSSI. Methods: This study builds on previous research in a prospective, longitudinal examination of implicit self-identification with NSSI in a large sample of middle school students. NSSI behavior and implicit NSSI associations were assessed annually in school at three time points. Results: Adolescents who engaged in NSSI exhibited stronger implicit self-identification with NSSI than adolescents who did not engage in NSSI. Moreover, implicit NSSI identification was stronger among adolescents who engaged in cutting, frequent NSSI, and recent NSSI. A reciprocal association was observed between NSSI frequency and implicit NSSI identification over 1 year. Notably, implicit NSSI identification uniquely and prospectively predicted engagement in NSSI over the subsequent year. Conclusions: Implicit self-identification with NSSI may track both trait-and state-related changes in the behavior and, importantly, may help predict continued engagement in NSSI.