Tremblay S, et al. - In this multi-cohort, case-control study, researchers ascertained if patients who sustain a mild traumatic brain injuries (mTBI) earlier in life fare better than patients who sustain a mTBI at an older age. The study sample consisted of participants randomly sampled from a population of patients with a history of mTBI. For this investigation, they enlisted two cohorts of aging participants (N = 74, mean [SD] = 61.16 [6.41]) matched in age and education levels that differed in only one respect: age at mTBI onset. One cohort in their early twenties (24.60 [6.34] y/o), the other in their early sixties (61.05 [4.90] y/o) sustained their concussion. The findings revealed a significant interaction on DWI measures of white matter integrity indicating larger anomalies in candidates who sustained a mTBI at a younger age. These results indicate that mTBI initiates a process of lifelong neurodegeneration that outweighs the hazards associated with maintaining an elderly mTBI. Implications are essential for the communities of young athletes who are subjected to the danger of mTBI in their sports practice and for retired athletes who are aged with a history of younger-age concussions.