Negative urgency and reward/punishment sensitivity in intermittent explosive disorder

Intermittent explosive disorder (IED) is the sole psychiatric diagnosis in which affective aggression is the cardinal symptom. Previous research has been equivocal with regard to the relationship between IED and impulsivity. This inconsistency may reflect the varied facets of impulsivity, with some aspects of impulsivity (e.g. negative urgency) as well as some overlapping, albeit distinct constructs (e.g. reward and punishment sensitivity) yet to be studied.

The present study compared individuals diagnosed with IED (n=81) with psychiatric controls (PCs; n=52) and healthy volunteers (HVs; n=58) on the impulsivity domains of negative and positive urgency, perseverance, sensation seeking, and premeditation, as well as on reward and punishment sensitivity. We hypothesized that individuals with IED would show greater negative and positive urgency, reward sensitivity, punishment sensitivity, with negative urgency independently predicting IED status. We also hypothesized that negative urgency would predict levels of anger, aggression, and aggression control among those with IED.

The IED participants reported greater negative urgency than both comparison groups, and greater levels of positive urgency, reward sensitivity, and punishment sensitivity compared to HVs. Further, heightened negative urgency was the sole predictor an IED diagnosis. Within the IED group negative urgency uniquely predicted decreased aggression control and increased trait anger.

Limitations included reliance on self-report measures to assess RS/PS, impulsivity, and aggression.

These findings suggest that negative urgency is a key factor associated with IED and is associated with dampened control of aggression within those with IED.