27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
Of 285 participants randomized (suvorexant, N = 142; placebo, N = 143), 277 (97%) completed the trial (suvorexant, N = 136; placebo, N = 141). 4 key findings →
Participants: 142 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
Narcolepsy type 1 is strongly associated with human leukocyte antigen (HLA)-DQB1*06:02; however, no significant associations between IH and HLA alleles have been reported. 4 key findings →
Design: meta-analysis Participants: 414 Evidence: high
Full summary, score breakdown and related studies → Original source
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
Baseline sleep disturbance was associated with a faster rate of longitudinal CSF Aβ42 decline. 4 key findings →
Design: longitudinal study Participants: 1,205 Evidence: moderate
Full summary, score breakdown and related studies → Original source
AD was characterized by longer time in bed, more bed exits, less snoring, and changes in estimated sleep states. 5 key findings →
Design: longitudinal study Participants: 13,588 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Twenty-five out of 44 completed the trial. 5 key findings →
Participants: 25 Evidence: high
Full summary, score breakdown and related studies → Original source
Our systematic review shows evidence for disruptions in (night-time) melatonin levels in AD as compared to age-matched controls. 3 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source
Polysomnography (PSG) studies of sleep changes in Alzheimer's disease (AD) have reported but not fully established the relationship between sleep disturbances and AD. 2 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source
SA may be a gender-dependent, age-dependent, and time-dependent risk factor for dementia. 2 key findings →
Design: cohort study Participants: 1,414 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Fifty-nine primary studies met all criteria. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
First, sleep problems are associated with accidents and human errors. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Light treatment alone did not improve nighttime sleep, daytime wake, or rest-activity rhythm. 4 key findings →
Participants: 16 Evidence: high
Full summary, score breakdown and related studies → Original source
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
Baseline EDS was associated with increased longitudinal Aβ accumulation in elderly persons without dementia, suggesting that those with EDS may be more vulnerable to pathologic changes associated with Alzheimer disease. 5 key findings →
Design: longitudinal study Participants: 283 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
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
Insomnia in elderly people has traditionally been regarded as inevitable and trivial. 2 key findings →
Design: longitudinal study Participants: 705 Evidence: moderate
Full summary, score breakdown and related studies → Original source
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
During a median of 10.8 years follow-up, sleeping more or fewer than 7 hours was associated with a higher dementia risk (hazard ratio [HR] for 5 vs 7 hours: 1.35, 95% confidence interval [CI] 1.11-1.64; HR for 9 vs 7 hours: 1.59; 95% CI 1.37-1.85) as was daytime napping (HR for often/all of the time vs never/rarely: 1.67; 95% CI 1.37-2.03). 4 key findings →
Design: longitudinal study Evidence: moderate
Full summary, score breakdown and related studies → Original source
We observed a dose-response association between higher alcohol consumption in 2006 and worse sleep quality in 2012 (Ptrend < 0·001), after adjusting for age, sex, socio-economic status, smoking status, physical activity, obesity, plasma lipid profiles, diabetes and hypertension. 5 key findings →
Design: cross-sectional Participants: 905 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Sleep duration exhibited a U-shaped association with SPARE-AD (p = 0.001), Trail Making Tests A and B, and the Digit Symbol Substitution Test (all p < 0.001). 5 key findings →
Participants: 38,816 Evidence: low
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 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 →