Comprehensive large-scale analyses reveal association between brain structure and cognitive ability during adolescence

Significant changes occur in brain structure and cognition during adolescence. Investigating their association can provide insight into brain-based cognitive development, yet previous studies are limited by narrow measures, small samples, and lacking focus on age-dependence. Using a large cohort (n = 8534, age 9-15) with structural MRI and diffusion imaging, we derive 16 regional metrics and integrate them via morphometric similarity networks to characterize 16,563 brain features. We apply large-scale models to investigate their associations with seven cognitive subtests and general intelligence (g), as well as age-dependence. Brain areas most strongly associated with cognition also show the greatest age-dependence of the associations, primarily in the frontal, temporal, and occipital lobes. Stronger and more age-dependent associations with cognition are observed for structural MRI measures and global hub measures, compared with diffusion-derived metrics and local measures, respectively. Overall, our study provides a comprehensive and reliable characterization of adolescent brain structure-cognition associations.