Focus on this: Intrinsic brain abnormalities could better characterize ADHD

Characteristics of the brain’s resting-state functional architecture are pertinent to understanding the relationship between the neural substrate and executive function in young patients with attention deficit hyperactivity disorder (ADHD), according to a study published on April 30 by Radiology.

Although resting-state functional MRI (rfMRI) studies have revealed that the brain’s frontostriatal circuit is implicated in helping to control behavior, the specific brain physiology that underlies ADHD is not well understood. 

The study’s lead author, Fei Li, PhD, of the West China Hospital of Sichuan University, and colleagues utilized rfMRI in a population of 65, as it is a newer technique that assesses neural function while the brain isn’t focused on specific tasks. This modality is particularly helpful when investigating the brain’s functional organization separate from task performance, wrote the researchers.

The study group included 33 boys with ADHD between the ages of six and 16 and 32 similarly aged, healthy controls. Because people with ADHD often have issues with executive function, Li and colleagues compared rfMRI results between the two groups and then correlated the findings with results from tests of executive function. Embodied in this term are mental processes such as planning, organizing, time management and regulating emotions.

Results indicated that patients with ADHD had altered structure and function in areas of the brain like the orbitofrontal cortex and the globus pallidus. The first is primarily involved with the cognitive processing during planning, while the latter area partakes in executive inhibitory control.

Li et al also discovered abnormalities in the connections between the resting-state brain networks that are associated with executive dysfunction. These abnormalities provide more insight into the widespread brain alterations that exist in those with ADHD than previous research, according to the authors.

“In summary, we found that children and adolescents with ADHD have altered regional brain function and aberrant FC in large-scale networks that were associated with executive dysfunction, suggesting that the characteristics of the brain’s resting-state functional architecture are relevant to understanding relationships between neural substrate and executive function in ADHD,” wrote the researchers.

They plan on studying changes in brain activity over time in ADHD patients and exploring potential differences of functional connectivity between the clinical subtypes of ADHD.

"Our results suggest the potential clinical utility of the rfMRI changes as a useful marker, which may help in diagnosis and in monitoring disease progression and, consequently, may inform timely clinical intervention in the future,” remarked senior author Qiyong Gong, MD, PhD, also of the West China Hospital of Sichuan University, in a press release.