Similar functions, different behaviors: New insights into the co-occurrence of eating disorders and nonsuicidal self-injury in adolescence

Objective: Self-destructive behaviors, including nonsuicidal self-injury (NSSI), restrictive eating, binge eating, and purging, are highly prevalent and comorbid. We provide a new perspective on this comorbidity by considering reinforcement functions of these behaviors.Methods: Participants included 457 adolescents who indicated how often they engaged in restrictive eating, binge eating, purging, and NSSI for reasons reflecting positive or negative reinforcement (with automatic or social contingencies). We explored patterns of functions across behaviors via multidimensional scaling and hierarchical clustering.Results: A two-cluster solution captured variability in functions across self-destructive behaviors. The first cluster included all social functions, and the second cluster included most automatic functions, regardless of the specific self-destructive behavior. Conclusions: Individuals who engage in one self-destructive behavior for social or automatic reinforcement are likely to engage in other behaviors for that same reason. Identifying and targeting shared functions in treatment could simultaneously reduce engagement in multiple harmful behaviors.