Abstract
Brain structural alterations in psychiatric disorders are being progressively elucidated through the analysis of large‐scale brain magnetic resonance imaging (MRI) data from multiple sites. However, biases arising from differences in scanning procedures and sample characteristics between MRI sites have compromised the reliability of the analyses and consistency of interpretation. The authors here intend to propose a method integrating harmonization based on multi‐site imaging of the same subject (traveling subject ; TS) and the statistical method ComBat‐GAM to assess disorder‐specific structural brain changes in psychiatric disorders. This method suggests the possibility of data harmonization without burdensome TS scans while reducing measurement bias. Furthermore, by estimating normative lifespan trajectories using nonlinear regression with large‐scale healthy control data, we can highlight disease‐common and ‐specific variation, enabling highly sensitive analysis beyond conventional meta‐analysis and flexible analysis, including the addition of new data. Based on the harmonized data, it is expected that the characteristics of brain structural changes for each psychiatric disorder will be clarified in the future, contributing to the elucidation of the pathophysiology of the disorders and the improvement of diagnostic accuracy.
