Sleep and Circadian Science

A new study published in the journal Neurology by researchers at UT Southwestern Medical Center finds that older adults with the weakest circadian activity rhythms had nearly 2.5 times the risk of developing dementia over subsequent years compared with peers with the strongest rhythms. Monitoring more than 2,000 dementia‑free participants around age 79 with chest‑worn ECG patches for about 12 days, the team also found that people whose daily activity peaked at 2:15 p.m. or later had a 45% higher dementia risk, though the authors stress the results show an association, not proof that circadian disruption causes dementia.