Response inhibition and attention deficit hyperactivity disorder with and without oppositional defiant disorder...

The study compared performance of children with high levels of attention deficit hyperactivity disorder (ADHD; n=22), children with ADHD and oppositional defiant disorder (ODD; n=19), and a control group (n=20) on a Go-No-go test in a self-paced and computer-paced condition. Each condition, in turn, was run in a reward and a nonreward condition. The children were recruited through screening of a school population without ADHD or ODD (N=450). Findings indicated that children having high levels of ADHD plus ODD showed poor impulse control in all 4 conditions. No poor impulse control was found in the group with high levels of ADHD. This group demonstrated slower RTs across the computer-paced conditions. Findings were discussed in terms of the response-inhibition hypothesis, as formulated by Barkley (1997), the delay-aversion theory (Sonuga-Barke, 1995), and the state-regulation theory (Van der Meere, 2002).