ABSTRACT
Objective: To investigate the clinical differences between intermittent explosive disorder (IED) (disorder of aggression primarily directed towards others) and nonsuicidal self-injury (NSSI) (disorder of aggression predominantly directed towards the self) in order to better understand the different clinical subtypes of aggression. Methods: We used treatment-seeking samples to compare demographic and clinical correlates between 82 participants with IED and 55 participants with NSSI. Results: The IED group was older, more likely to be male, in a relationship, and employed than the NSSI group. With respect to clinical variables, the NSSI group had more severe depressive symptoms and more social adjustment difficulties. Regarding psychiatric co-morbidities, the IED group had higher rates of generalized anxiety disorder. On the other hand, the NSSI group had higher rates of major depressive disorder, agoraphobia, substance use disorder, and bulimia nervosa. Conclusions: Individuals with NSSI may benefit from better management of psychiatric comorbidities, specifically depressive symptoms and social adjustment difficulties. Conversely, the treatment of individuals with IED may be improved by targeting comorbid generalized anxiety disorder. Our results provide important insight for the development of tailored interventions for specific subtypes of aggression.