27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
For cognitively unimpaired individuals, living in the most disadvantaged neighborhoods was associated with significantly lower cerebral volumes, after controlling for maximal premorbid (total intracranial) volume. 4 key findings →
Design: cohort study Participants: 951 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
Functional imaging data indicate that the pathophysiology of schizophrenia reflects aberrant activity in, and integration of, the components of distributed circuits involving the prefrontal cortex, hippocampus and certain subcortical structures. 1 key finding →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Numerous studies have reported a smaller hippocampal volume in Alzheimer's disease (AD) patients than in aging controls. 2 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Brain abnormalities are present in nonpsychotic first-degree relatives of patients with schizophrenia and are most pronounced in the hippocampus. 2 key findings →
Participants: 1,065 Evidence: low
Full summary, score breakdown and related studies → Original source
Using VBM-DARTEL, when corrected for multiple comparisons, significant volume differences were detected between groups in different regions and more specifically in hippocampus with ROI analyses. 3 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Cardiovascular activity has been shown to be positively associated with gray and white matter volume of, amongst others, frontal and temporal brain regions in older adults. 4 key findings →
Design: randomized controlled trial Evidence: high
Full summary, score breakdown and related studies → Original source
Hippocampal volume was the primary determinant of memory decline, whereas executive function (EXEC) decline was related to multiple brain components. 5 key findings →
Design: longitudinal study Participants: 103 Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
During the period of longitudinal observation, which averaged 32.6 months, 27 of the 80 MCI patients became demented. 4 key findings →
Design: longitudinal study Evidence: moderate
Full summary, score breakdown and related studies → Original source Free full text
The number of ECT sessions and electrode placement impacts the extent and laterality of hippocampal enlargement, but volume change is not positively associated with clinical outcome. 4 key findings →
Design: longitudinal study Participants: 281 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Patients with preserved cognition and mild-verbal memory/semantic fluency were younger (mean [SD] age, 36.5 [9.8] years and 38.2 [11.1] years) and had shorter disease duration (mean [SD] 8.0 [7.3] years and 8.3 [7.6] years) compared with patients with mild-multidomain (mean [SD] age, 42.6 [11.2] years; mean [SD] disease duration, 12.8 [9.6] years; P < .001), severe-executive/attention (mean [SD] age, 42.9 [11.7] years; mean [SD] disease duration, 12.2 [9.5] years; P < .001), and severe-multidomain (mean [SD] age, 44.0 [11.0] years; mean [SD] disease duration, 13.3 [10.2] years; P < .001) phenotypes. 3 key findings →
Design: cross-sectional Participants: 235 Evidence: moderate
Full summary, score breakdown and related studies → Original source
This longitudinal quantitative magnetic resonance imaging study of 24 patients with mild temporal lobe epilepsy shows an ipsilateral hippocampal volume decrease of 9% (range, -30 to +0.5%; p = 0.002, paired t test) over a period of 3.5 +/- 0.7 years. 2 key findings →
Design: longitudinal study Participants: 24 Evidence: moderate
Full summary, score breakdown and related studies → Original source
A higher omega-3 index was correlated with larger total normal brain volume and hippocampal volume in postmenopausal women measured 8 years later. 3 key findings →
Evidence: low
Full summary, score breakdown and related studies → Original source
Rates of hippocampal atrophy (%/year) were 0.0 +/- 0.8 in the absent, 1.7 +/- 0.4 in the moderate, and 3.6 +/- 1.0 in the severe (mean +/- SD) tertile. 2 key findings →
Participants: 323 Evidence: moderate
Full summary, score breakdown and related studies → Original source Full text may need a subscription
Although the effect of major depressive disorder on amygdala volume remains to be conclusively established, inclusion of the amygdala with the hippocampus appears to have decreased the likelihood of detecting volumetric differences in either structure. 4 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
The meta-analyses revealed structural brain abnormalities in MDD that are distinct from those observed in BD. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
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
Schizophrenia is associated with a bilateral volumetric reduction of the hippocampus and probably of the amygdala as well. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Poor memory ability and small hippocampal volume measurements in magnetic resonance images co-occur in neurological patients. 5 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
There is evidence that excessive stress exposure of the brain, mediated through the neurotoxic effects of cortisol and possibly neuroinflammation, causes damage to brain structure and function: the glucocorticoid cascade hypothesis. 5 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source
Little work has directly examined the course of hippocampal volume in children and adults with childhood maltreatment-related posttraumatic stress disorder (PTSD). 2 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Animal models point towards a key role of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-I (IGF-I) and vascular endothelial growth factor (VEGF) in mediating exercise-induced structural and functional changes in the hippocampus. 2 key findings →
Participants: 21 Evidence: low
Full summary, score breakdown and related studies → Original source
We performed a systematic review and meta-analysis of neural predictors of response to the most commonly used, evidence based treatments in clinical practice, namely pharmacological and psychological therapies. 5 key findings →
Design: systematic review Evidence: high
Full summary, score breakdown and related studies → Original source
Several magnetic resonance imaging studies have reported hippocampal volume reduction in patients with schizophrenia, but other studies have reported contrasting results. 2 key findings →
Design: meta-analysis Evidence: high
Full summary, score breakdown and related studies → Original source
Our findings reveal that specific gut microbial features are closely associated with cognitive impairment and decreased hippocampal volume, which may play an important role in dementia development. 4 key findings →
Design: case-control study Participants: 90 Evidence: moderate
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
9 of the 492 studies in this tag, 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 9. The same 9 appear here every time.
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 →