Cross-sectional brain age assessments are limited in predicting future brain change
The concept of brain age (BA) describes an integrative imaging marker of brain health, often suggested to reflect ageing processes. However, the degree to which cross-sectional MRI features, including BA, reflect past, ongoing and future brain changes across different tissue types from macro- to microstructure remains controversial. Multimodal imaging data of 39,325 UK Biobank participants, aged 44-82 years at baseline and 2,520 follow-ups within 1.12-6.90 years, provide insufficient evidence that BA reflects the rate of brain ageing.