ADHD subtypes: do they differ in their executive functioning profile?

The study focused on understanding if children with two types of Attention Deficit Hyperactivity Disorder (ADHD), namely the combined subtype (ADHD-C) and the inattentive subtype (ADHD-I), show differences in their ability to control behavior, pay attention, and manage tasks (known as executive functioning). This is important because executive function is a key factor in how well someone with ADHD can perform daily activities. Fortunately, executive function can improve with interventions like exercise.

The authors compared three groups of boys: those with normal development, those with ADHD-C, and those with ADHD-I. Each group had 16 boys. They were all of the same age and intelligence level, and some had other behavior disorders. This careful matching was done to ensure that the differences observed were due to ADHD types and not other factors.

Despite the detailed grouping and controls, the study found that ADHD-C children differed from normal controls only in tasks that required inhibiting responses, not in all areas of executive functioning. Surprisingly, children with ADHD-C and those with ADHD-I did not show major differences in their executive functions. This suggests that the two subtypes may not be as distinct in their executive functioning as previously thought.

In conclusion, the study suggests that the executive functioning profile of children with ADHD-C is not as broad as believed and does not clearly set them apart from children with ADHD-I. This finding is significant as it challenges the current understanding of the distinctiveness of ADHD subtypes in terms of executive functioning.

The Barkley et al. study highlights that executive function is a stronger predictor of job performance than IQ, especially in adults with ADHD. This underscores the importance of executive function, which the current study examines in children with ADHD. While Barkley et al. focused on adults, our study provides insights into the developmental aspects of ADHD and executive function in children.

Similarly, the Benzing et al. study shows that exercise can improve executive functions in children with ADHD, aligning with the notion that executive function, a key focus of the current study, can be enhanced. This broader context of research, including our study, indicates a growing understanding of how ADHD affects executive functions and how these can be improved through different means, such as physical activity.