Fig. 1: Overview of study design.

A White matter tracts used for brain age modeling: 54 white matter tracts grouped into 7 distinct systems, for which normative models of brain age were constructed using tract-specific features. B Tract profiles of fractional anisotropy (FA). 100 segments (nodes) were evenly sampled along each unilateral tract, generating 200 FA values per bilateral tract. C Predictive models of brain age were generated using FA tract-profiles of the specific tracts from the participants in Human Connectome Project in Development (HCP-D) dataset with 5-fold cross-validation. One whole-brain and 29 specific-tract normative developmental models were established separately. Using models trained on HCP-D dataset, brain age gaps (BAGs) based on whole-brain and individual tracts were computed for each participant in the independent Healthy Brain Network pediatric mental health (HBN) and Adolescent Brain Cognitive Development (ABCD) datasets. Associations of the BAGs with behavioral and clinical assessments were investigated. Abbreviations: HH healthy-persistent; PH disorder-remitted; HP disorder-new-onset; PP disorder-persistent; KSADS-5 Kiddie Schedule for Affective Disorders and Schizophrenia for DSM-5; AF Arcuate Fasciculus; FAT Frontal Aslant Tract; PAT Parietal Aslant Tract; SLF Superior Longitudinal Fasciculus; IFOF Inferior Fronto Occipital Fasciculus; ILF Inferior Longitudinal Fasciculus; UF Uncinate Fasciculus; MdLF Middle Longitudinal Fasciculus; C_FPH Cingulum Frontal Parahippocampal; C_FP Cingulum Frontal Parietal; C_PH Cingulum Parahippocampal; C_PHP Cingulum Parahippocampal Parietal; C_PO Cingulum Parolfactory; F Fornix; CST Corticospinal Tract; OR Optic Radiation; VOF Vertical Occipital Fasciculus; TR_A Thalamic Radiation Anterior; TR_P Thalamic Radiation Posterior; TR_S Thalamic Radiation Superior; CS_A Corticostriatal Tract Anterior; CS_P Corticostriatal Tract Posterior; CS_S Corticostriatal Tract Superior; CC Corpus Callosum; CC_Body CC Body; CC_Major CC Forceps Major; CC_Minor CC Forceps Minor; CC_Tap CC Tapetum. Icons in Fig. 1C were made from https://www.svgrepo.com/. The person (by CyCraft, https://www.svgrepo.com/svg/393155/person-filled) and artificial-brain-computer (by howcolour, https://www.svgrepo.com/svg/416386/artificial-brain-computer) icons were adapted in color and are used under the Creative Commons license (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/deed.en).