27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
Study objectives Mounting evidence implicates disturbed sleep or lack of sleep as one of the risk factors for Alzheimer's disease (AD), but the extent of the risk is uncertain. 4 key findings →
Design: systematic review Participants: 69,216 Evidence: high
Full summary, score breakdown and related studies → Original source
Sleep fragmentation in older adults is associated with incident AD and the rate of cognitive decline. 5 key findings →
Design: cohort study Participants: 97 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Study objectives To examine the association of sleep complaints reported at baseline (insomnia complaints and excessive daytime sleepiness (EDS)) and medication, with cognitive decline in community-dwelling elderly. 4 key findings →
Design: longitudinal study Participants: 4,894 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Study objectives Sleep duration has been associated with risk of dementia and stroke, but few studies have investigated the relationship between sleep duration and brain MRI measures, particularly in middle age. 3 key findings →
Design: prospective cohort Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
The pooled sample comprised 4657 participants (30% women) aged ≥ 60 years (mean age was 74 years at sleep assessment). 5 key findings →
Design: cohort study Participants: 2,374 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Study objectives To determine the effect of self-reported clinical diagnosis of obstructive sleep apnea (OSA) on longitudinal changes in brain amyloid PET and CSF biomarkers (Aβ42, T-tau, and P-tau) in cognitively normal (NL), mild cognitive impairment (MCI), and Alzheimer's disease (AD) elderly. 2 key findings →
Design: longitudinal study Participants: 516 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
The study included 44 iRBD patients (81.8% males, mean age 71.0 ± 6.4 years), 55 HC (66.3% males, mean age 69.1 ± 5.5 years), and 28 AD patients (82.1% males, mean age of 70.4 ± 6.7 years). iRBD patients showed significantly higher plasma NfL and GFAP levels and similar pTau181 levels compared to HC. 5 key findings →
Design: cross-sectional Participants: 44 Evidence: low
Full summary, score breakdown and related studies → Original source
Study objectives To examine associations between positive airway pressure (PAP) therapy, adherence and incident diagnoses of Alzheimer's disease (AD), mild cognitive impairment (MCI), and dementia not otherwise specified (DNOS) in older adults. 5 key findings →
Participants: 1,057 Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
Study objective Obstructive sleep apnea (OSA) contributes to the development of systemic hypertension, and hypertension strongly predicts the development of white matter change (WMC). 2 key findings →
Design: cross-sectional Participants: 289 Evidence: low
Full summary, score breakdown and related studies → Original source
Based on actigraphy as an objective measure of sleep time, melatonin is not an effective soporific agent in people with Alzheimer's disease. 3 key findings →
Participants: 157 Evidence: high
Full summary, score breakdown and related studies → Original source
A total of 8994 and 14 720 participants were involved in the change-to-change analyses and change-to-dementia analyses, respectively. 5 key findings →
Design: longitudinal study Participants: 720 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Four men, aged 67-72 years, had 4-month to 6-year histories of injuring themselves or their spouses with aggressive behaviors during sleep, often during attempted dream enactment. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Cardiac 123I-MIBG findings are similar among idiopathic RBD and the syndromes of PD and DLB, but differ from those of PSP and MSA. 4 key findings →
Design: cross-sectional Participants: 95 Evidence: low
Full summary, score breakdown and related studies → Original source
Study objectives Emerging evidence suggests a role for sleep in contributing to the progression of Alzheimer disease (AD). 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
This study provided a preliminary examination of indices of obstructive sleep apnea (OSA) and sleep disruptions in adults with Down syndrome (DS), and their associations with Alzheimer's disease (AD) pathology and symptomatology. 3 key findings →
Design: longitudinal study Participants: 22 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Study objectives To evaluate the role of orexin-A with respect to cerebrospinal fluid (CSF) Alzheimer disease (AD) biomarkers, and explore its relationship to cognition and sleep characteristics in a group of cognitively normal elderly individuals. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
Circadian rhythms in elderly patients with severe dementia and behavioral disorders such as wandering, agitation and/or delirium were examined. 1 key finding →
Participants: 24 Evidence: low
Full summary, score breakdown and related studies → Original source
Study objectives We conducted the present study to determine whether psychiatric disorders are commonly associated with sleep apnea in Veterans Health Administration beneficiaries. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Mechanisms regulating human sleep and physiology have evolved in response to rhythmic variation in environmental variables driven by the Earth's rotation around its axis and the Sun. 1 key finding →
Participants: 26 Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
We found that tau phosphorylation undergoes sleep-driven circadian variations as it is hyperphosphorylated during sleep but not during acute sleep deprivation. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Kening Jiang, Daniel D Callow, Adam P Spira; The Role of Sleep in Dementia Prevention: Building the Case for Causality, Sleep, , zsaf285, https://doi.org/1 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
The relationship of sleep apnea to age, sex, and Alzheimer's dementia was investigated in 45 elderly subjects and 10 young males, all nonobese, normotensive, nonsmoking, with no sleep complaints and no medical problems other than Alzheimer's disease. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Study objective To determine the frequency of rapid eye movement (REM) sleep behavior disorder (RBD) and REM sleep without atonia among patients with Alzheimer disease and control subjects. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
We measured 24-hour circadian-rhythm patterns of activity and sleep/wake activity in a group of nursing-home patients (58 women and 19 men with a mean age of 85.7 years). 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Our study is the first one showing that dietary supplements improve cognition and sleep in a mouse model of DS. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Free full text links and the Full text may need a subscription label come from Unpaywall, Europe PMC and OpenAlex records of free copies, checked 10 Oct 2026. A study with neither is unknown, not paywalled. Show only studies that are free to read
This is alzhub's own score. It is not an official metric, not an impact factor, and no journal, publisher or ranking body endorses it. We built it so that a reader who is not a scientist can tell a landmark trial from a conference abstract without having to already know the difference. Every point comes from one of 20 components, all of them printed on the study itself, so you can disagree with our arithmetic rather than having to trust the total.
Journals are placed in ordered tiers, never given a numeric impact factor — we could not verify current impact factors from a source we control, and an invented one would be worse than none. Tier 1 is the top-tier general journals (NEJM, The Lancet, JAMA, Nature, Science, Nature Medicine); tier 2 is the leading specialty journals; tier 3 is every other peer-reviewed journal. A separate part scores how much the journal's own papers are cited, which tells the tier-3 journals apart.
Two rules we don't bend. First, we never fill in a missing value: if a record does not state a sample size or a design, that component scores zero, and if we simply have no data for a part, such as a citation count, that part is left out and the study is scored on the parts we could check. The study card says which. Second, anything that is not a peer-reviewed article is capped at 16/100 and carries a warning chip — so a conference abstract or a company press release can never outrank a peer-reviewed paper, no matter how good it looks.
We rank a rigorous null result — a good trial showing that something does not work — above an early positive finding. Someone deciding whether to buy a supplement is served by that, and the rigour is already counted by the design and journal components.
The score is computed from the published data alone and is reproducible: the same file always yields the same numbers.
See the whole rubric drawn out → — four charts covering all 27,380 studies: how the scores are spread and where the cap bites, which of the 20 components the library is strong and weak on, which subjects rest on stronger evidence, and what kinds of study each subject is actually built from.
This is a large sample of the Alzheimer's literature, not an exhaustive index of it. It holds 27,380 records, built mostly from automated pulls of Europe PMC (60.6% of the library) and OpenAlex (18.6%), plus smaller pulls from PubMed, Crossref and medRxiv. If a study, a drug, or a finding isn't here, that is not evidence it doesn't exist in the literature — it may simply not have been pulled in yet.
1,032 records (3.8% of the library) are not peer-reviewed — 962 of those are preprints posted before any journal review, and the rest are conference abstracts, regulatory notices and reports. Every study card on this page states its status plainly, and the score above is capped for anything that isn't a peer-reviewed article.
See the full, machine-readable breakdown of this library's coverage →