The JAMA Neurology study found that both sleeping six hours or less and sleeping nine hours or more per night were associated with more depressive symptoms and more napping compared to sleeping seven or eight hours per night.
Notes on verification
Directly confirmed by PubMed abstract and JAMA Neurology publication (Winer et al., 2021), corroborated by independent secondary summary from Alzheimer Europe. [tier=gold indep_score=0.983 clusters=3 claim_tier=notable | framework convergence=single on Winer et al. 2021 JAMA Neurology study using A4 study cohort data (upstreams: Winer JR, Deters KD, Kennedy G, Jin M, Goldstein-Piekarski A, Poston KL, Mormino EC. Association of Short and Long Sleep Duration With Amyloid-β Burden and Cognition in Aging. JAMA Neurol. 2021;78(10), Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study) — publishers independent, evidence may not be | kind=attributed eligibility=high]
Sources
- How much sleep keeps cognitive decline at bay? - Harvard Health (seed:psychology_and_neuroscience)
- https://pubmed.ncbi.nlm.nih.gov/34459862/ (corroboration)
- https://www.alzheimer-europe.org/news/new-research-jama-neurology-explores-impact-sleep-duration-amyloid-accumulation-and-cognitive?language_content_entity=en (corroboration)
- https://jamanetwork.com/journals/jama/article-abstract/2785733 (corroboration)