27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
Dementia is a key part of survival in Parkinson disease and must be planned for in services for this condition. 1 key finding →
Design: cohort study Participants: 140 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
More than three quarters of this representative PD cohort developed dementia during the 8-year study period. 2 key findings →
Design: longitudinal study Participants: 224 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Significantly more patients with MCI than without MCI at baseline (10 of 37 [27.0%] vs 1 of 145 [0.7%]; relative risk, 39.2 [95% CI, 5.2-296.5]; P Conclusions and relevance Mild cognitive impairment at PD diagnosis predicts a highly increased risk for early dementia. 1 key finding →
Design: cohort study Participants: 182 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Psychotic symptoms affect most patients with PD, with increased risk in those with higher age at onset, need for high doses of dopaminergic drugs, and probable REM sleep behavior disorder. 3 key findings →
Design: cohort study Participants: 137 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Early PD-MCI, regardless of persistence or reversion to normal cognition, has prognostic value for predicting dementia in patients with PD. 2 key findings →
Participants: 178 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Of 230 patients, 211 (92%) died during the study period. 2 key findings →
Participants: 230 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Forty-three patients with PD were demented at follow-up evaluation, equivalent to an incidence rate of 95.3 per 1,000 person-years (95% CI, 68.2 to 122.0). 2 key findings →
Participants: 171 Evidence: moderate
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Apathy is a persistent behavioural feature in PD with a high incidence and prevalence over time. 3 key findings →
Design: longitudinal study Participants: 139 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
The findings demonstrate a twofold increase in the proportion with cognitive impairment in subjects with early, untreated Parkinson disease (PD) compared to controls. 4 key findings →
Participants: 196 Evidence: moderate
Full summary, score breakdown and related studies → Original source
The aim of this study was to establish the rate of progression from mild cognitive impairment (MCI) to dementia in patients with Parkinson's disease (PD). 3 key findings →
Participants: 34 Evidence: low
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These in vivo data support the role of Aβ pathology in the etiology and highlight the potential utility of CSF Aβ42 as an early prognostic biomarker of dementia associated with PD. 3 key findings →
Participants: 20 Evidence: moderate
Full summary, score breakdown and related studies → Original source
We found that despite a similar severity of dementia, patients with dementia with Lewy bodies (DLB) had more cortical atrophy than patients with Parkinson disease with dementia (PDD), indicating different brain substrates underlying dementia in the two syndromes. 5 key findings →
Participants: 20 Evidence: low
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Twenty-two patients with Parkinson's disease drawn from a community-based study were followed prospectively until their deaths. 2 key findings →
Participants: 18 Evidence: low
Full summary, score breakdown and related studies → Original source
Nearly ¾ of the PD cohort reported falling after 8 years of follow-up. 1 key finding →
Participants: 32 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Cholinesterase inhibitors with additional nicotinic activity, such as galantamine, may be useful in PD patients with dementia (PDD) since stimulation of nicotinic receptors may prevent the down-regulation that is likely to accompany cholinesterase inhibition and facilitate dopamine release in the striatum. 4 key findings →
Design: open-label trial Evidence: low
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Both motor and neuropsychiatric symptoms contributed to institutionalization, but the presence of hallucinations was the strongest predictor. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The objective of this study was to assess the temporal relationship between changes in predominant motor symptoms and incident dementia in Parkinson's disease (PD). 4 key findings →
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 →