MRI brain scans from children, adolescents, and adults with ADHD found age-related differences in parts of the basal ganglia, which regulates voluntary movement. The findings suggest that variations in the structure of the pallidum could contribute to the changing symptoms of ADHD throughout an individual’s life.
- ADHD is defined by impulsivity and poor attention.
- Symptoms of ADHD vary throughout life, but children are highly affected.
- The pallidum is responsible for voluntary movement, and gray matter deficits in this region are associated with ADHD severity.
Attention-deficit/hyperactivity disorder (ADHD) first appears in childhood but often persists into adulthood. Symptoms vary across the lifespan and may be attributed to structural and functional differences in the brain. Dysfunction of the basal ganglia structures, responsible for motor control, learning, and executive function, has been seen in children with ADHD.
The Link Between Brain Regions and Symptom Severity
Scientists used magnetic resonance imaging (MRI) scans of children, adolescents, and adults with ADHD from the New York University Child Study Center. Voxel-based morphometric analysis was performed to investigate differences between the three age groups. They also explored correlations between brain regions altered by age and ADHD symptom severity.
Gray matter volume differences were found in ADHD patients in parts of the basal ganglia, thalamus, insula, temporal cortex, and cerebellum. The pallidum, part of the basal ganglia, is known to regulate voluntary movement, and some patients with ADHD experience restlessness and excessive movement. In this study, scientists found that patients with more severe ADHD symptoms had a greater reduction in gray matter volume in the right pallidum, indicating a relationship between this region’s structure and an individual’s behavior.
Widespread Structural Changes in ADHD
This study found widespread structural changes among people with ADHD. Overall, this implicates gray matter deficits in the pallidum, specifically, with clinical signs of ADHD. The authors acknowledge that their sample consisted mostly of male participants, and this may influence the results. With apparent differences in how males and females manifest ADHD symptomatology, more research on females will be necessary for future studies.
Agoalikum, E., Klugah-Brown, B., Wu, H., Hu, P., Jing, J., & Biswal, B. (2023). Structural differences among children, adolescents, and adults with attention-deficit/hyperactivity disorder and abnormal Granger causality of the right pallidum and whole-brain. Frontiers in Human Neuroscience, 17, 1076873. https://doi.org/10.3389/fnhum.2023.1076873