Increased brain age and relationships with blood-based biomarkers following concussion in younger populations.

"data availability statement the pediatric data that support the findings of this study will be openly available in fitbir at fitbir nih gov reference number fitbir-study0000339"

"Declarations Conflicts of interestDr. Meier receives compensation as a member of the Clinical and Scientific Advisory Board for Quadrant Biosciences Inc. No other authors report any competing interests. Ethics approvalAll procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The pediatric study was approved by the University of New Mexico School of Medicine Institutional Review Board. All participants provided written informed consent or assent depending on age with parental consent for everyone under 18 years of age. The CARE study was approved by the Medical College of Wisconsin Institutional Review Board and the Department of Defense Human Research Protection Office. All participants provided written informed consent. Conflicts of interest Dr. Meier receives compensation as a member of the Clinical and Scientific Advisory Board for Quadrant Biosciences Inc. No other authors report any competing interests."

"This research was supported by grants from the National Institutes of Health (https://www.nih.gov) to Andrew R. Mayer (Grant numbers NIH 01 R01 NS098494-01A1, R01 NS098494-03S1A1, P30 GM122734, and S10 OD025313) and to Timothy Meier (Grant number R21NS118169). This publication was made possible in part by support from the Grand Alliance CARE Consortium, funded by the NCAA and the Department of Defense. The US Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702-5014, USA. This work was supported by the Office of the Assistant Secretary of Defense for Health Affairs through the Psychological Health and Traumatic Brain Injury Program under Award no. W81XWH-14-2-0151. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense (Defense Health Program funds). The NIH had no role in study review, data collection and analysis, decision to publish, or preparation of the manuscript."