Cerebrospinal fluid neurofilament light chain is a marker of aging and white matter damage.

"Declaration of Competing Interest: None."

"Funding/Support This work was funded by the Bright Focus grant A2021012F (KLM), the Alzheimer’s Association grant BAND-19–613876 (BAG), and the National Institute of Health (NIH) grants R01NR012907 (BA), R01NR012657 (BA), R01NR014449 (BA), R01AG052550 (BA), R01AG057680 (BA), P01AG00391 (JCM), P01AG026276 (JCM), P01AG005681 (JCM), and K01AG053474 (BAG), U19AG032438 (BAG), R03AG050921 (SES), K23AG053426 (SES). This work was also supported by the generous support of Barnes-Jewish Hospital, the Washington University Institute of Clinical and Translational Sciences Foundation (UL1 TR000448), the Knight Alzheimer Disease Research Center, the Hope Center for Neurological Disorders, the Paula and Rodger O. Riney Fund, the Daniel J. Brennan MD Fund, and the Fred Simmons and Olga Mohan Fund. The team thanks all participants involved in this study. Support for Florbetapir F18 (18F-AV-45) and Flortaucipir F18 (18F-AV-1451) was provided by Avid Radiopharmaceuticals, a wholly owned subsidiary of Eli Lilly."