Average volumetric changes are close to the limit of detection by MRI methods. 2 key findings →
Design: systematic review Participants: 1,424 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.
This series of meta-analyses examined structural abnormalities of the hippocampus and other brain regions in persons with PTSD compared to trauma-exposed and non-exposed control groups. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Previous studies in humans have shown the presence of an age-related reduction of hippocampal (HC) volume, as well as the presence of reduced HC volume in psychiatric populations suffering from schizophrenia, depression or post-traumatic stress disorder. 3 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Structural imaging studies investigating hippocampal volumes in patients suffering from major depression have yielded mixed results. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Patients with chronic schizophrenia displayed bilateral hippocampal volume reduction. 4 key findings →
Design: cross-sectional Participants: 89 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Schizophrenia and psychotic bipolar disorder are characterized by morphometric distinctions in ventricular and hippocampal regions. 1 key finding →
Participants: 243 Evidence: low
Full summary, score breakdown and related studies → Original source
Structural and functional magnetic resonance imaging (fMRI) was performed on 21 healthy elderly controls, 14 subjects with mild cognitive impairment (MCI) and 15 patients with mild Alzheimer's disease (AD) to investigate changes in fMRI activation in relation to underlying structural atrophy. 2 key findings →
Participants: 14 Evidence: low
Full summary, score breakdown and related studies → Original source
Aberrations in hippocampal asymmetry and left hippocampal volumes were found for adolescent heavy drinkers. 5 key findings →
Participants: 16 Evidence: low
Full summary, score breakdown and related studies → Original source
The present findings emphasize that patients with reduced hippocampal volumes show more executive dysfunctions than their counterparts. 2 key findings →
Participants: 34 Evidence: low
Full summary, score breakdown and related studies → Original source
These findings demonstrate a disruption in fornix integrity in patients with schizophrenia. 4 key findings →
Design: cross-sectional Evidence: low
Full summary, score breakdown and related studies → Original source
The mind involves the whole body and two-way communication between the brain and the cardiovascular, immune, and other systems via neural and endocrine mechanisms. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Brain areas implicated in the stress response include the amygdala, hippocampus, and prefrontal cortex. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
40/100
Alzheimer's disease is the most common neurodegenerative disorder in the elderly. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The findings are consistent with the presence of smaller hippocampal and amygdalar volumes in patients with dissociative identity disorder, compared with healthy subjects. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
In spite of a relatively small sample size, the presence of the met-BDNF allele was found associated with a reduced volume of the hippocampal formation in healthy volunteers and may represent a vulnerability factor for the development of disease processes associated with the dysfunction of this brain region. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
From clinical studies it is known that recurrent depressive episodes associate with a reduced hippocampal volume. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
In the current experiment we conducted a multi-level analysis of age-related characteristics in the hippocampus of young adult (3 months), middle-aged (12 months), and old (24 months) Fisher 344xBrown Norway hybrid (FBNF1) rats. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Antidepressants protect against hippocampal volume loss in humans and reverse stress-induced atrophic changes in animals thus supporting the hypothesis that the pathophysiology of stress-related disorders such as depression involves reductions in neuronal connectivity and this effect is reversible by antidepressant treatment. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The serotonin system modulates affective, cognitive and behavioral processes. 1 key finding →
Evidence: low
Full summary, score breakdown and related studies → Original source
The hippocampus (HC) and associated neural structures are hypothesized to contribute to individual differences in human spatial navigation. 4 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
The concept of amnestic mild cognitive impairment (MCI) describes older people who show a decline predominantly in memory function, but who do not meet criteria for dementia. 5 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
These data support the view that heavy drinking exerts a unique and selectively injurious effect on the hippocampus. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Ts65Dn, a well-characterized animal model for Down syndrome, has three copies of the distal end of mouse chromosome 16 and therefore has segmental trisomy for orthologs for nearly half of the genes located on human chromosome 21. 2 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Characteristically arising in response to overwhelmingly terrifying events, post-traumatic stress disorder (PTSD) is a disorder of memory: sufferers seemingly relive their trauma in the form of involuntary recollection. 5 key findings →
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 →