Neural and psychophysiological markers of delay aversion in attention-deficit hyperactivity disorder

Delay aversion (DAv) is thought to be a crucial factor in the manifestation of impulsive behaviors in patients with attention-deficit/hyperactivity disorder (ADHD). The imposition of delay is predicted to elicit negative emotional reactions in ADHD. The present study offers a multimodal approach to the investigation of DAv. Twelve adult patients with ADHD and 12 matched healthy controls were tested on a new task with several levels of anticipated delays during functional magnet resonance imaging (fMRI). Behavioral measures of delay discounting, DAv, and delay frustration were collected. Skin conductance and finger pulse rate were assessed. Results indicated a group difference in response to changes in delay in the right amygdala: For control participants activity decreased with longer delays, whereas activity tended to increase for ADHD patients. The degree of amygdala increase was correlated with the degree of behavioral DAv within the ADHD group. Patients also exhibited increased emotional arousal on physiological measures. These results support the notion of an exacerbated negative emotional state during the anticipation and processing of delay in ADHD.