AUTHOR=Jockwitz Christiane , Mérillat Susan , Liem Franziskus , Oschwald Jessica , Amunts Katrin , Jäncke Lutz , Caspers Svenja 

TITLE=Generalizing Longitudinal Age Effects on Brain Structure – A Two-Study Comparison Approach

JOURNAL=Frontiers in Human Neuroscience

VOLUME=15

YEAR=2021

URL=https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2021.635687

DOI=10.3389/fnhum.2021.635687

ISSN=1662-5161

ABSTRACT=<p>Cross-sectional studies indicate that normal aging is accompanied by decreases in brain structure. Longitudinal studies, however, are relatively rare and inconsistent regarding their outcomes. Particularly the heterogeneity of methods, sample characteristics and the high inter-individual variability in older adults prevent the deduction of general trends. Therefore, the current study aimed to compare longitudinal age-related changes in brain structure (measured through cortical thickness) in two large independent samples of healthy older adults (<italic>n</italic> = 161 each); the Longitudinal Healthy Aging Brain (LHAB) database project at the University of Zurich, Switzerland, and 1000BRAINS at the Research Center Juelich, Germany. Annual percentage changes in the two samples revealed stable to slight decreases in cortical thickness over time. After correction for major covariates, i.e., baseline age, sex, education, and image quality, sample differences were only marginally present. Results suggest that general trends across time might be generalizable over independent samples, assuming the same methodology is used, and similar sample characteristics are present.</p>