Affective inhibitory control in adults with attention deficit hyperactivity disorder: abnormalities in electrocortical late positivity.

Boys afflicted with ADHD (Attention-deficit/hyperactivity disorder) are characterized by deficient response inhibition and reduced electrocortical late positivity when presented with facial expressions of anger. This deficit might contribute to their problems in social interactions. We conducted the present event-related potential study with 15 men suffering from ADHD and 15 healthy controls in order to investigate whether similar dysfunctions are present in adult ADHD. The participants underwent an emotional version of a Go/NoGo task while event-related potentials (ERPs) were recorded. They were instructed to inhibit a motor response to one of four facial emotional expressions: anger, fear, sadness, or happiness. There were no behavioral differences in inhibitory control between the ADHD and the control group. However, the patients showed a reduced right parietal late positivity when instructed to inhibit a response to negative emotions. Obviously, the patients have learned to compensate for their deficit on a behavioral level, while it is still visible on the electrocortical level in this relatively simple task. Interestingly, the reduced positivity correlated with lowered self-reported emotional intelligence in the ADHD group.