Latent structure of intermittent explosive disorder in an epidemiological sample

Intermittent explosive disorder (IED) is characterized by distinct periods of impulsive aggression marked by assaultive acts or destruction of property. However, impulsive aggression is also a feature of other disorders, all of which are viewed in diagnostic nomenclature as qualitatively distinct from IED. This state of affairs is problematic for categorical models unless it is demonstrated empirically that IED-related impulsive aggression is qualitatively distinct from impulsive aggression observable in other axis I and II disorders. The current study addresses this question using taxometric methods to examine the latent structure of IED. Participants were respondents on the Collaborative Psychiatric Epidemiological Surveys, which obtained data on a range of disorders including intermittent explosive disorder (N=20,013) and a range of psychological variables. Indicator variables used were drawn from the survey items and submitted to select taxometric methods (MAMBAC and MAXEIG) to determine the relative fits of a taxonic versus dimensional model. The results of taxometric analyses provided support for a taxonic, rather than dimensional, structure for IED symptoms in the epidemiological sample. Taxon group membership was associated with treatment seeking, family history of anger attacks, lower age of onset of anger attacks, and male biological sex, providing strong support for the validity of the IED taxon.