30,980 Alzheimer's and dementia studies in plain English, each scored out of 100.
A total of 5971 titles were reviewed and 60 studies were included in the analysis, 36 RCTs and 24 observational studies. 5 key findings →
Design: systematic review Participants: 5,971 Evidence: high
Full summary, score breakdown and related studies → Original source
In total, 30 studies were included comprising 14,997 subjects. 5 key findings →
Participants: 14,997 Evidence: low
Full summary, score breakdown and related studies → Original source
The mean rate of brain atrophy per year was 0.76% [95% CI, 0.63-0.90] in the active treatment group and 1.08% [0.94-1.22] in the placebo group (P = 0.001). 2 key findings →
Design: randomized controlled trial Participants: 271 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
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 disorders, particularly insomnia and obstructive sleep apnea, are increasingly implicated as significant contributors to cognitive decline, dementia, and neurodegenerative diseases such as Alzheimer's disease (AD) and vascular cognitive impairment and dementia (VCID). 4 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
A relationship between sleep disorders and cognitive dysfunctions was reported in Parkinson's Disease (PD), however, some studies did not confirm the link. 4 key findings →
Design: meta-analysis Participants: 54 Evidence: high
Full summary, score breakdown and related studies → Original source
Seventeen risk/protective factors met criteria for the algorithm to estimate risk for any dementia including age, sex, education, hypertension, midlife obesity, midlife high cholesterol, diabetes, insufficient physical activity, depression, traumatic brain injury, atrial fibrillation, smoking, social engagement, cognitive engagement, fish consumption (diet), stroke, and insomnia. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Age-related hearing loss is linked to loneliness and poorer cognitive health, but it remains unclear whether loneliness helps explain associations between hearing difficulties and cognitive performance or dementia, and whether these patterns reflect causal pathways or shared underlying liability. 4 key findings →
Design: longitudinal study Participants: 10,375 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Among older women, those with sleep-disordered breathing compared with those without sleep-disordered breathing had an increased risk of developing cognitive impairment. 4 key findings →
Design: cross-sectional Participants: 60 Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
Fifty-nine primary studies met all criteria. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Hearing loss is highly prevalent in dementia; however, people with dementia are less likely to use hearing aids consistently than people with intact cognition are. 2 key findings →
Design: randomized controlled trial Evidence: high
Full summary, score breakdown and related studies → Original source
Our search yielded 182 meta-analyses meeting the inclusion criteria, of which 59 were selected to calculate DALY-weighted risk factors for a composite outcome. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Excluding participants with prevalent dementia, n = 1,161 individuals were included. 5 key findings →
Design: longitudinal study Participants: 1,161 Evidence: moderate
Full summary, score breakdown and related studies → Original source
High blood pressure increases the risks of stroke, dementia, and neurocognitive dysfunction. 2 key findings →
Participants: 124 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
Sleep duration had an inverted U-shape relationship with cognitive scores (P <.001); and sleep quality had a positive linear relationship with cognitive scores (P <.001). 5 key findings →
Design: longitudinal study Participants: 10,768 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Alzheimer's disease and related dementias is a major public health burden-compounding over upcoming years due to longevity. 1 key finding →
Design: longitudinal study Participants: 30,097 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Midlife insomnia (fully adjusted hazard ratio = 1.24, 95% confidence interval = 1.02-1.50) and late-life terminal insomnia (fully adjusted odds ratio = 1.94, 95% confidence interval = 1.08-3.49) were associated with a higher dementia risk. 3 key findings →
Design: longitudinal study Participants: 1,446 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Their results on motor testing from the preceding years were plotted, and then assessed with regression analysis, to determine when markers first deviated from normal values. 3 key findings →
Design: cohort study Participants: 78 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Dementia is a major contributor to dependence and disability in older people, with aging societies characterized by growing numbers of people living with the condition. 5 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source
Modifiable risk factors identified in this study, especially those with high-level evidence, should be considered in dementia prevention. 2 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
REM sleep behaviour disorder (RBD) is a parasomnia characterized by the loss of normal skeletal muscle atonia during REM sleep with prominent motor activity accompanying dreaming. 4 key findings →
Design: longitudinal study Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Several studies report an association between REM Sleep Behavior Disorder (RBD) and neurodegenerative diseases, in particular synucleinopathies. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Although bright light therapy seems a promising treatment for sleep problems, research shows inconclusive results. 4 key findings →
Design: meta-analysis Participants: 1,154 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
Smoking, head injury, pesticide exposure, and farming are potential risk factors for idiopathic REM sleep behavior disorder. 1 key finding →
Design: case-control study Participants: 694 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Nocturnal hypoxemia was related to greater decline on the 3 MS . 5 key findings →
Design: longitudinal study Participants: 2,636 Evidence: moderate
Full summary, score breakdown and related studies → Original source
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 30,980 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 30,980 records, built mostly from automated pulls of Europe PMC (65.2% of the library) and OpenAlex (16.4%), 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.
1,040 records (3.4% of the library) are not peer-reviewed — 965 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 →
Newest studies, as a dated timeline → Atom feed Where this research is being discussed: events