Abstract
Intermittent Explosive Disorder (IED) is a common, chronic, and impairing psychological condition characterized by recurrent, affective aggressive behavior. IED is associated with a host of cognitive and affective symptoms not included in the diagnostic criteria which may be a valuable indicator of heterogeneity in IED-such information can be useful to enhance understanding and treatment of this disorder in mental health settings. A preliminary investigation conducted on cognitive-affective symptom heterogeneity in individuals with a history of IED demonstrated that level of emotional dysregulation primarily differentiated IED subgroups, however the sample size was limited, and almost half of the individuals did not have current IED (only lifetime IED). The present study addressed these limitations by conducting a latent class analysis of cognitive-affective symptoms among a large (n = 504) sample of individuals diagnosed with current IED. The latent IED classes were then externally validated on several adverse outcomes, historical precursors, and demographic variables. Statistical and clinical indicators supported a four-class model, with classes primarily distinguished by patients' severity of emotion dysregulation. The two moderate emotion-dysregulated classes both endorsed callous-unemotional traits and low empathy relative to other classes, a finding which differs from the initial investigation. An external validation of the four classes revealed that they significantly differed on severity outcomes (e.g., aggression, suicide attempts, antisocial behavior, global functioning, comorbidities) and historical precursors (e.g., aversive parental care, childhood maltreatment). These findings provide further insight into the heterogeneity within IED and the associations of such variability with important precursors and clinical outcomes.