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

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.

Risk factors for non-motor symptoms in Parkinson's disease

✓ Peer-reviewed alzhub usefulness score 62 out of 100. The Lancet. Neurology 2018-04-23

Non-motor symptoms (NMS) of Parkinson's disease can be predominant as the disease advances, thereby constituting a major source of disease burden for patients and caregivers. 2 key findings →

Design: longitudinal study Evidence: moderate

Parkinson's disease and dementia with Lewy bodies are currently defined by their clinical features, with α-synuclein pathology as the gold standard to establish the definitive diagnosis. 5 key findings →

Evidence: low

Quantifying the risk of neurodegenerative disease in idiopathic REM sleep behavior disorder

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Neurology 2008-12-24

Although we have found a slightly lower risk than other reports, the risk of developing neurodegenerative disease in idiopathic REM sleep behavior disorder is substantial, with the majority of patients developing Parkinson disease and Lewy body dementia. 2 key findings →

Participants: 113 Evidence: low

Cognition and anatomy in three variants of primary progressive aphasia

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Annals of neurology 2004-03-01

We performed a comprehensive cognitive, neuroimaging, and genetic study of 31 patients with primary progressive aphasia (PPA), a decline in language functions that remains isolated for at least 2 years. 3 key findings →

Participants: 31 Evidence: low

Comparisons of ADNC in typical amnestic versus atypical aphasic dementia and of TDP in type A versus type C revealed fundamental biological and clinical differences, suggesting that members of each pair may constitute distinct clinicopathologic entities despite identical downstream proteinopathies. 1 key finding →

Design: longitudinal study Participants: 68 Evidence: moderate

A systematic literature review and meta-analyses (where appropriate) were performed and the GRADE approach was used to update the previous American Academy of Sleep Medicine Practice Parameters on the treatment of intrinsic circadian rhythm sleep-wake disorders. 5 key findings →

Design: meta-analysis Evidence: high

A 12-year population-based study of psychosis in Parkinson disease

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Archives of neurology 2010-08-01

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

Frontotemporal lobar degeneration: a consensus on clinical diagnostic criteria

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Neurology 1998-12-01

The criteria ought to provide the foundation for research work into the neuropsychology, neuropathology, genetics, molecular biology, and epidemiology of these important clinical disorders that account for a substantial proportion of cases of primary degenerative dementia occurring before the age of 65 years. 2 key findings →

Evidence: low

Idiopathic Parkinson's disease (PD) is a neurodegenerative disorder associated with akinesia, tremor and rigidity. 4 key findings →

Design: longitudinal study Evidence: moderate

For neuropsychology measures, we noted the earliest significant differences between mutation carriers and non-carriers 5 years before expected onset, when differences were significant for all measures except for tests of immediate recall and verbal fluency. 2 key findings →

Participants: 220 Evidence: low

The Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) are the most commonly used scales to test cognitive impairment in Lewy body disease (LBD), but there is no consensus on which is best suited to assess cognition in clinical practice and most sensitive to cognitive decline. 4 key findings →

Design: cohort study Participants: 197 Evidence: moderate

Intronic expansion of the GGGGCC hexanucleotide repeat within the C9ORF72 gene causes frontotemporal dementia and amyotrophic lateral sclerosis/motor neuron disease in both familial and sporadic cases. 4 key findings →

Participants: 361 Evidence: moderate

Neuroinflammation in the form of microglial activation is present in synucleinopathies and is a potential therapeutic target to halt or delay the neurodegenerative process. 4 key findings →

Design: case-control study Participants: 20 Evidence: moderate

Possible association between PM2.5 and neurodegenerative diseases: A systematic review

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Environmental research 2021-12-31

Air pollution is one of the most serious environmental problems that afflict our planet and one of the greatest risk factors for human health. 3 key findings →

Design: systematic review Participants: 20 Evidence: high

Mediterranean diet adherence is associated with lower increase in pPD probability over time and lower possible/probable pPD and PD/DLB incidence in older Mediterranean people. 5 key findings →

Design: longitudinal study Participants: 21 Evidence: moderate

According to our findings, the identification of autonomic dysfunction seems to be of great importance in clinical practice, not only to avoid falls and other complications, but also as a possible predictor of survival. 4 key findings →

Design: longitudinal study Participants: 36 Evidence: moderate

Parkinson's Progression Markers Initiative brain autopsy program

✓ Peer-reviewed alzhub usefulness score 62 out of 100. Parkinsonism & related disorders 2022-07-01

We report on the initial 17 (11 male:6 female) brain autopsies from across Europe and the United States in the Parkinson's Progression Markers Initiative (PPMI). 5 key findings →

Design: longitudinal study Participants: 15 Evidence: moderate

Cognitive impairment is a common non-motor symptom in people with Parkinson's disease (PD) and is associated to poor clinical outcomes. 5 key findings →

Design: longitudinal study Evidence: moderate

Discriminating α-synuclein strains in Parkinson's disease and multiple system atrophy

✓ Peer-reviewed alzhub usefulness score 61 out of 100. Nature 2020-02-05

Synucleinopathies are neurodegenerative diseases that are associated with the misfolding and aggregation of α-synuclein, including Parkinson's disease, dementia with Lewy bodies and multiple system atrophy 1 . 4 key findings →

Evidence: low

From across this tag

10 of the 1,058 studies in this tag that have a study page, picked by a fixed rule (a hash of each study's address), not by score or date; each page of this list shows a different 10. The same 10 appear here every time.

↑ 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 30,180 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 30,180 records, built mostly from automated pulls of Europe PMC (64.2% of the library) and OpenAlex (16.9%), 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.

1,037 records (3.4% of the library) are not peer-reviewed — 964 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