The University of Fukui finds that Children with ADHD show smaller brain volume in specific regions

A research group led by Assistant Professor Qiulu Shou and Associate Professor Yoshifumi Mizuno from the Research Center for Child Mental Development at the University of Fukui, in collaboration with Professor Yoshiyuki Hirano from the Research Center for Child Mental Development at Chiba University and Professor Kuriko Kagitani-Shimono from the United Graduate School of Child Development at the University of Osaka, announced on September 5 that they have constructed a "Child Developmental" database containing numerous MRI (magnetic resonance imaging) data, including that of children with attention-deficit/hyperactivity disorder (ADHD), and revealed characteristics of brain structure in children with ADHD using analysis incorporating the traveling-subject (TS) method. The study found that children with ADHD show smaller brain volume in the right middle temporal gyrus. These findings are expected to lead to objective diagnosis and early diagnosis of ADHD. The results were published in Molecular Psychiatry on August 8.

ADHD is a developmental disorder characterized by an inability to maintain concentration and restlessness, found in approximately 7% of children. Due to this, children with the disorder face daily difficulties which can lead to concurrent mental health conditions such as depression.

Diagnosis is conducted primarily through interviews and behavioral observation, making it subjective, meaning that more objective and quantitative diagnostic methods are needed. While numerous studies using MRI have been conducted for this purpose, results from previous studies have not always been consistent, with the types of MRI equipment used (measurement bias) potentially affecting the results.

The research group has been developing a "Child Developmental" database aimed at elucidating the neural mechanisms of neurodevelopmental disorders, including ADHD. In this study, the research group validated the accuracy of the TS method to correct for this measurement bias. The basic data required for the TS method was collected with the cooperation of 14 typically developing adults who visited all three facilities—the University of Fukui, Chiba University, and the United Graduate School of Child Development at the University of Osaka—within three months, where MRI imaging was performed using all four devices.

Additionally, MRI data from 178 typically developing children and 116 children with ADHD registered in the database was compared and corrected using the TS method. The analysis software "FreeSurfer" was used to measure gray matter volume in the brain. For comparison with the TS method, data was also corrected and compared using the conventional correction method "ComBat." The volumes of a total of 82 regions, including 68 cortical and 14 subcortical areas, were analyzed.

The results showed that corrected data was more reliable than raw data. Furthermore, it was confirmed that the TS method could prevent the overcorrection that occurs with conventional correction methods, thereby improving reliability.

Comparison between children with ADHD and typically developing children using the TS method revealed that children with ADHD showed significantly smaller brain volumes centered in the frontotemporal regions, with particularly notable differences in the middle temporal gyrus.

According to Shou: "In the future, we would like to use the TS method not only for brain structure research but also for brain function research to clarify the characteristics of ADHD. The right middle temporal gyrus shows relatively strong differences between ADHD and typical development. Such results could potentially serve as biomarkers, and we hope to find more objective indicators."

Journal Information
Publication: Molecular Psychiatry
Title: Brain structure characteristics in children with attention-deficit/hyperactivity disorder elucidated using traveling-subject harmonization
DOI: 10.1038/s41380-025-03142-6