Get help now — free helplines

You can call any of these for free. You do not need a diagnosis, an appointment, or a crisis to call — questions and plain exhaustion are reasons enough.

  • Alzheimer's Association 24/7 Helpline 800-272-3900 24 hours a day, 365 days a year Free, confidential support and information for people with dementia, caregivers, families and the public. Master's-level clinicians. Also Spanish.
  • 988 Suicide & Crisis Lifeline 988 24/7 Call or text 988, or chat at 988lifeline.org. For anyone in emotional distress or a mental-health crisis, including caregivers.
  • Alzheimer's Foundation of America (AFA) Helpline 866-232-8484 9:00 am - 9:00 pm ET, seven days a week Licensed social workers providing support, info and referrals. Also text message and web chat. Text: 646-586-5283

In a medical emergency, call 911. More numbers, and what each line does, on the help page.

Find studies

Showing 51–75 of 522 studies in How common it is (page 3 of 21) · 27,380 in the whole library · How the 0–100 score works

Browse by subject, author or institution

Each number is how many studies that link shows, with your other filters kept.

What “How common it is” covers

How common it is — Counting patterns across whole populations: who gets dementia, at what age, and how that is changing.

A note on reading research. One study is rarely the final word.

We try to note the size of a study, whether it was in humans or animals, and how early-stage the finding is. If a summary here doesn't make that clear, treat it with extra caution and check the original source.

Individual statins were not significantly associated with risk of Parkinson's disease, rheumatoid arthritis, venous thromboembolism, dementia, osteoporotic fracture, gastric cancer, colon cancer, lung cancer, melanoma, renal cancer, breast cancer, or prostate cancer. 3 key findings →

Design: cohort study Participants: 692 Evidence: moderate

A randomized trial of risperidone, placebo, and haloperidol for behavioral symptoms of dementia

✓ Peer-reviewed alzhub usefulness score 70 out of 100. Neurology 1999-09-01

Low-dose risperidone (mean 1.1 mg/d) was well tolerated and associated with reductions in the severity and frequency of behavioral symptoms, particularly aggression, in elderly patients with dementia. 5 key findings →

Participants: 344 Evidence: low

Pooled clinical and neuropathologic data from 3 prospective cohort studies indicate that TBI with LOC is associated with risk for Lewy body accumulation, progression of parkinsonism, and PD, but not dementia, AD, neuritic plaques, or neurofibrillary tangles. 5 key findings →

Design: cohort study Participants: 7,130 Evidence: moderate

Cancer survivors had a lower risk of Alzheimer's disease than those without cancer, and patients with Alzheimer's disease had a lower risk of incident cancer. 5 key findings →

Design: cohort study Participants: 1,278 Evidence: moderate

Our findings suggest that clinicians should consider sedative-associated, hypoxic, and septic delirium, which often co-occur, as distinct indicators of acute brain injury and seek to identify all potential risk factors that may impact on long-term cognitive impairment, especially those that are iatrogenic and potentially modifiable such as sedation. 2 key findings →

Design: cohort study Participants: 1,048 Evidence: moderate

Contribution of Modifiable Midlife and Late-Life Vascular Risk Factors to Incident Dementia

✓ Peer-reviewed alzhub usefulness score 69 out of 100. JAMA Neurology 2025-07-01

A total of 7731 participants were included in analysis of risk factors measured at age 45 to 54 years (4494 female [58%]; 2207 Black [29%]; 5524 White [71%]), 12 274 contributed to analysis of risk factors measured at age 55 to 64 years (6698 female [55%]; 2886 Black [24%]; 9388 White [76%]), and 6787 contributed to analysis of risk factors measured at age 65 to 74 years (3764 female [56%], 1375 Black [20%]; 5412 White [80%]). 3 key findings →

Design: cohort Participants: 12,274 Evidence: moderate

Influence of education and occupation on the incidence of Alzheimer's disease

✓ Peer-reviewed alzhub usefulness score 69 out of 100. JAMA 1994-04-01

The data suggest that increased educational and occupational attainment may reduce the risk of incident AD, either by decreasing ease of clinical detection of AD or by imparting a reserve that delays the onset of clinical manifestations. 2 key findings →

Design: cross-sectional Participants: 593 Evidence: moderate

Diabetes, even prediabetes and changes of diabetes-related biochemical indicators, predicted increased incidence of cognitive impairment and dementia. 3 key findings →

Design: systematic review Evidence: high

Patients with osteoarthritis had excess all cause mortality compared with the general population (standardised mortality ratio 1.55, 95% confidence interval 1.41 to 1.70). 2 key findings →

Design: cohort study Participants: 1,163 Evidence: moderate

Each level increase in the severity of atherosclerosis or arteriolosclerosis was associated with significantly higher odds of Alzheimer's disease dementia (odds ratio [OR] for atherosclerosis 1·33, 95% CI 1·11-1·58; OR for arteriolosclerosis 1·20, 1·04-1·40). 4 key findings →

Design: cohort study Participants: 1,143 Evidence: moderate

ADNI has demonstrated the feasibility and utility of multicenter PET studies and is helping to clarify the role of biomarkers in the study of aging and dementia. 3 key findings →

Design: longitudinal study Participants: 100 Evidence: moderate

APOE4 homozygozity represents a distinct genetic form of Alzheimer's disease

✓ Peer-reviewed alzhub usefulness score 69 out of 100. Nature medicine 2024-05-06

This study aimed to evaluate the impact of APOE4 homozygosity on Alzheimer's disease (AD) by examining its clinical, pathological and biomarker changes to see whether APOE4 homozygotes constitute a distinct, genetically determined form of AD. 2 key findings →

Participants: 3,297 Evidence: low

Is dementia incidence declining?: Trends in dementia incidence since 1990 in the Rotterdam Study

✓ Peer-reviewed alzhub usefulness score 69 out of 100. Neurology 2012-05-02

In the 1990 subcohort (25,696 person-years), 286 persons developed dementia, and in the 2000 subcohort (8,384 person-years), 49 persons. 4 key findings →

Design: cohort study Participants: 5,727 Evidence: moderate

Incidence of Dementia over Three Decades in the Framingham Heart Study

✓ Peer-reviewed alzhub usefulness score 68 out of 100. New England Journal of Medicine 2016

This long-running Massachusetts study tracked dementia rates over more than 30 years and found that a given person's chance of developing dementia at a given age has been steadily falling since the late 1970s. The decline was seen mainly in people with at least a high school education. 4 key findings →

Design: cohort Participants: 5,205 Evidence: high

Inequalities in dementia incidence between six racial and ethnic groups over 14 years

✓ Peer-reviewed alzhub usefulness score 68 out of 100. Alzheimer's & Dementia 2016-03

This large study followed over 274,000 members of a single California health system for 14 years and found striking differences in dementia rates by race and ethnicity. 5 key findings →

Design: cohort Participants: 274,283 Evidence: high

Patients with the repeat expansion had significantly more co-morbid FTD than patients without the repeat (50%vs 12%), and a distinct pattern of non-motor cortex changes on high-resolution 3 T magnetic resonance structural neuroimaging. 3 key findings →

Design: longitudinal study Participants: 49 Evidence: moderate

Incidence and Prevalence of Frontotemporal Dementia: A Systematic Review and Meta-Analysis

✓ Peer-reviewed alzhub usefulness score 67 out of 100. JAMA Neurology 2025-11-01

In this systematic review and meta-analysis, estimates indicate that FTD is comparable in frequency to dementia with Lewy bodies and occurs at higher rates than progressive supranuclear palsy, corticobasal syndrome, and amyotrophic lateral sclerosis. 5 key findings →

Design: meta-analysis Evidence: moderate

↑ Change the filters

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 →

Newest studies, as a dated timeline →    Atom feed