Forty-four participants were recruited between September 2019 and June 2022. 5 key findings →
Evidence: high
Full summary, score breakdown and related studies → Original source
Research
27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
As the literature related to cognitive reserve (CR) in individuals with frontotemporal dementia (FTD) is only emerging, a clear consensus on the relationship among CR proxies, brain status, and clinical performance has not been reached. 2 key findings →
Design: systematic review Participants: 1,423 Evidence: high
Full summary, score breakdown and related studies → Original source
For ACD, novel loci identified were associated with energy transport (SEMA4D), neuronal excitability (ANO3), amyloid deposition in the brain (RBFOX1), and magnetic resonance imaging markers of small vessel disease (SVD; HBEGF). 5 key findings →
Participants: 800,597 Evidence: low
Full summary, score breakdown and related studies → Original source
Though still small, the current body of RCT evidence indicates that CT is safe and modestly effective on cognition in patients with mild to moderate PD. 4 key findings →
Participants: 272 Evidence: high
Full summary, score breakdown and related studies → Original source
WMH were associated with increased risk of cognitive dysfunction and could become a neuroimaging indicator of dementia. 3 key findings →
Design: meta-analysis Participants: 19,040 Evidence: high
Full summary, score breakdown and related studies → Original source
White matter hyperintensities are associated with an increased risk of all-dementia and Alzheimer's disease in the general population. 3 key findings →
Design: meta-analysis Participants: 3,913 Evidence: high
Full summary, score breakdown and related studies → Original source
In the replication stage, we performed genotyping of significant and suggestive results from the discovery stage. 2 key findings →
Design: meta-analysis Participants: 1,743 Evidence: high
Full summary, score breakdown and related studies → Original source
This study investigated the potential association between levels of plasma neurofilament light chain (NfL) and cognitive function in patients suffering from Parkinson's disease (PD) in P.R. 3 key findings →
Design: meta-analysis Participants: 168 Evidence: high
Full summary, score breakdown and related studies → Original source
A total of 15 eligible studies were included in the meta-analysis. 5 key findings →
Design: systematic review Participants: 109 Evidence: high
Full summary, score breakdown and related studies → Original source
We screened 18,884 papers and included 135 studies. 5 key findings →
Design: meta-analysis Participants: 135 Evidence: high
Full summary, score breakdown and related studies → Original source
The outcomes were better among patients treated with rivastigmine than among those who received placebo; however, the differences between these two groups were moderate and similar to those reported in trials of rivastigmine for Alzheimer's disease. 3 key findings →
Participants: 541 Evidence: low
Full summary, score breakdown and related studies → Original source Free full text
MRI features of cerebral small vessel disease (CSVD), i.e. white matter hyperintensities, lacunes, microbleeds, perivascular spaces, and cerebral atrophy, may be associated with clinical events, but the strength of these associations remains unclear. 5 key findings →
Design: systematic review Participants: 16,458 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
Frontotemporal dementia (FTD) is a complex disorder characterised by a broad range of clinical manifestations, differential pathological signatures, and genetic variability. 4 key findings →
Design: meta-analysis Participants: 3,526 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
Hypertension significantly increases the risk of vascular dementia. 4 key findings →
Design: meta-analysis Participants: 768 Evidence: high
Full summary, score breakdown and related studies → Original source
Substantial variation in the prevalence of dementia in Parkinson's disease (PDD) has been reported. 2 key findings →
Design: systematic review Participants: 1,767 Evidence: high
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Vascular cognitive impairment (VCI) describes a broad spectrum of cognitive impairments caused by cerebrovascular disease, ranging from mild cognitive impairment to dementia. 4 key findings →
Design: meta-analysis Participants: 2,193 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
These data demonstrate that donepezil is an effective and well-tolerated treatment for VaD and show it may have an important place in the management of this condition. 5 key findings →
Participants: 603 Evidence: high
Full summary, score breakdown and related studies → Original source
In a 24-week, randomized, double-blind, placebo-controlled, multicenter study of rivastigmine, 487 patients with dementia associated with Parkinson disease underwent assessment of attention on the Cognitive Drug Research computerized cognitive assessment system before dosing and 16 and 24 weeks later. 2 key findings →
Participants: 487 Evidence: high
Full summary, score breakdown and related studies → Original source
111,485 articles were initially retrieved; 288 full articles were reviewed and 89.6% subsequently deemed ineligible due to exclusion of participants with co-existence of dementia and Parkinsonism. 5 key findings →
Design: randomized controlled trial Participants: 16 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
Among 2 184 847 Danish citizens aged between 65 and 95 years, there were 3024 individuals with DLB (mean [SD] age, 78 [6], 1894 [62.6%] male) and 3808 with PDD (mean [SD] age, 78 [6], 2400 [63.0%] male) who were matched with 30 240 and 38 080 controls, respectively. 5 key findings →
Design: case-control study Participants: 3,024 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Ann Neurol 2018;84:737-748. 1 key finding →
Design: meta-analysis Participants: 443 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
Dementia has been increasingly more recognized to be a common feature in patients with Parkinson's disease (PD), especially in old age. 4 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source Full text may need a subscription
We did not apply any language or date restrictions to the electronic searches, and we did not use any methodological filters as a method to restrict the search overall. 3 key findings →
Design: meta-analysis Participants: 70 Evidence: high
Full summary, score breakdown and related studies → Original source Free full text
76/100
Cognitive impairment is a central non-motor symptom of Parkinson's disease (PD), and there are no established treatments. 4 key findings →
Design: meta-analysis Participants: 679 Evidence: high
Full summary, score breakdown and related studies → Original source
Where “Free full text” comes from
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
How the 0–100 score works — and why some entries are capped
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.
- Journal tier up to 10 pts
- Journal's citation record up to 4 pts
- Study design up to 12 pts
- Strength of evidence up to 5 pts
- Peer-review validation up to 10 pts
- How recent up to 5 pts
- Sample size up to 4 pts
- Effect reported up to 3 pts
- Studied in people up to 3 pts
- Randomised / blinded up to 2 pts
- Times cited up to 7 pts
- Citations per year up to 5 pts
- Impact for its field and year up to 6 pts
- Cited by studies here up to 6 pts
- Still being cited up to 4 pts
- Senior author's track record up to 4 pts
- Institution's track record up to 3 pts
- Multi-centre collaboration up to 3 pts
- Indexed in PubMed up to 2 pts
- Free to read up to 2 pts
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.
What this library is — and isn't
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 →