Circadian rhythm disturbances have been associated with these symptoms. 2 key findings →
Design: randomized controlled trial Evidence: high
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Research
27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
The suprachiasmatic nucleus (SCN) is considered to be the endogenous clock of the brain, essential for the ovulation cycle and the temporal organization of sleep-wake patterns, among other things. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source Full text may need a subscription
In major depression, decreased hippocampal volume has been attributed to hypercortisolemia, a frequent sign of the disorder, because in animals an excess of corticosteroids has led to dendritic atrophy, astrogliosis and loss of neurons in this brain region. 1 key finding →
Participants: 15 Evidence: low
Full summary, score breakdown and related studies → Original source
43/100
Light is known to be an important modulator of circadian rhythms. 2 key findings →
Participants: 22 Evidence: low
Full summary, score breakdown and related studies → Original source
The brains of 46 control subjects and 21 Alzheimer's disease (AD) patients were studied to determine whether there are age-related or AD-related changes in the vasoactive intestinal polypeptide (VIP) neuron population of the human suprachiasmatic nucleus (SCN). 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
ACTH release results in the release of corticosteroids from the adrenal that, subsequently, through mineralocorticoid and glucocorticoid receptors, exert negative feedback on, among other things, the hippocampus, the pituitary and the hypothalamus. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The pineal gland is a central structure in the circadian system which produces melatonin under the control of the central clock, the suprachiasmatic nucleus (SCN). 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The circadian rhythm of the pineal gland hormone, melatonin is generated within the hypothalamic suprachiasmatic nuclei (SCN), site of the circadian clock. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
The suprachiasmatic nucleus, considered to be the endogenous circadian clock in the mammalian brain, shows morphological changes with aging, which become even more pronounced in Alzheimer's disease (AD). 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
Sleep-wake rhythm disturbances in patients with Alzheimer's disease (AD) make a strong demand on caregivers and are among the most important reasons for institutionalization. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
Increased levels of circulating AVP are also associated with the risk for suicide. 1 key finding →
Evidence: low
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 →