Frontal alpha-asymmetry in adults with attention deficit hyperactivity disorder: replication and specification.

Recent findings suggest that adults suffering from attention deficit hyperactivity disorder (ADHD) display an atypical pattern of hemispheric asymmetry, assessed through the alpha band in resting-state electroencephalogram. In the context of the approach-withdrawal model of hemispheric asymmetry, this pattern has been identified as a correlate of approach-related behavior, particularly in anterior brain regions. The current study sought to replicate previous findings on alpha asymmetry in ADHD, and to specify them based on the assumption that ADHD represents a disorder of excessive approach tendencies. A group of ADHD patients (n=19) was compared to a group of healthy controls (n=19) on measures of alpha asymmetry and aggression, an approach-related trait. Observed region-specific group differences in alpha asymmetry approximated assumptions of the approach-withdrawal model. In addition ADHD subjects displayed elevated levels of a subcomponent of aggression. These results provide support for a conceptualization of ADHD as a disorder of excessive approach tendencies.