- 815studies on this subject, of 27,380 in the library
- 789peer-reviewed
- 1976–2026years published
- 54median usefulness score out of 100
These counts and lists are worked out from the library itself each time the page loads. A score rates how much weight a study can bear — its design, journal, evidence and recency — not whether its result is good news. How we score a study. For a plain-English guide to this subject, see Getting a diagnosis.
The 20 highest-scoring studies
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Amyloid PET Quantitation and Centiloid Thresholds in the Diagnosis of Alzheimer Disease: An Individual Participant Data Meta-Analysis
This large analysis of amyloid PET scans found that scans could be confidently read as negative below a Centiloid value of 11 and positive above 26. Scans in the 11 to 26 range should be interpreted with caution depending on the context, which matters for how amyloid PET results are used in diagnosis.
- One hundred years of schizophrenia: a meta-analysis of the outcome literature
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Blood phosphorylated tau 181 as a biomarker for Alzheimer's disease: a diagnostic performance and prediction modelling study using data from four prospective cohorts
This study, using data from four prospective cohorts, tested how well a blood measure of phosphorylated tau 181 (p-tau181) matched established spinal-fluid (CSF) and PET brain-scan markers of Alzheimer's disease, and whether it could be used in prediction models of change over time. Our record holds only the study's methods, not its results, so it cannot tell you how accurate the blood test was — check the original paper before drawing any conclusion. It evaluates a diagnostic test and does not test any treatment, cure or prevention.
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Monetary costs of dementia in the United States
This study estimated that dementia affected 14.7% of Americans over 70 in 2010 and cost between $157 billion and $215 billion yearly. It measures the economic burden of dementia but does not treat, cure or prevent it.
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Alzheimer disease in the United States (2010-2050) estimated using the 2010 census
This study estimated that in 2010 there were 4.7 million individuals aged 65 or older with Alzheimer's disease dementia in the United States, and projected that the total number would reach 13.8 million by 2050. It provides prevalence projections for planning purposes but does not test any treatment, cure, or prevention.
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Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial
In 9,361 adults aged 50+ with hypertension (but no diabetes or prior stroke), aiming for a systolic blood pressure below 120 mm Hg instead of below 140 did not significantly reduce probable dementia, the trial's main cognitive outcome (7.2 vs 8.6 cases per 1000 person-years; HR 0.83, 95% CI 0.67–1.04). The intensive target did reduce mild cognitive impairment (HR 0.81, 95% CI 0.69–0.95), a secondary outcome. The authors note the trial was stopped early with fewer dementia cases than expected and "may have been underpowered" for dementia, so the dementia result is unresolved rather than negative.
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Clinical diagnostic criteria for dementia associated with Parkinson's disease
This task force developed clinical diagnostic criteria for probable and possible dementia associated with Parkinson's disease, based on a systematic literature review and group consensus. It reports that the incidence of dementia in PD is increased up to six times and point-prevalence is close to 30%, but it does not address treating, curing, or preventing Alzheimer's disease.
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Change in end-of-life care for Medicare beneficiaries: site of death, place of care, and health care transitions in 2000, 2005, and 2009
This study of Medicare beneficiaries found that a lower proportion died in an acute care hospital in 2009 and 2005 compared with 2000, although intensive care unit use and health care transitions in the last month of life increased. It concerns end-of-life care and reports nothing about treating, curing, or preventing Alzheimer's disease.
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Mini-Mental State Examination (MMSE) for the detection of dementia in clinically unevaluated people aged 65 and over in community and primary care populations
This meta-analysis examined studies comparing the Mini-Mental State Examination against a clinical reference standard for detecting all-cause dementia and subtypes. It is about diagnostic test accuracy and does not address treating, curing, or preventing Alzheimer's disease.
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Incident dementia and blood pressure lowering in the Hypertension in the Very Elderly Trial cognitive function assessment (HYVET-COG): a double-blind, placebo controlled trial
In this double-blind, placebo-controlled trial of 3,336 elderly people with high blood pressure (systolic 160–200 mm Hg), treatment lowered systolic pressure by 15 mm Hg more than placebo at 2 years, but the authors concluded it "does not statistically reduce incidence of dementia". Follow-up averaged only 2.2 years because the trial was stopped early, and the authors say the negative result "might have been due to the short follow-up… or the modest effect of treatment". They add that the findings, "when included in a meta-analysis, might support" blood-pressure treatment to reduce dementia.
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Plasma p-tau181 accurately predicts Alzheimer's disease pathology at least 8 years prior to post-mortem and improves the clinical characterisation of cognitive decline
In 115 people who had blood drawn 8, 4 and 2 years before death and were then autopsied, plasma p-tau181 matched Alzheimer's brain pathology better than their clinical diagnosis did, and told Alzheimer's apart from other brain pathologies with high accuracy (AUC 97.4%, 95% CI 94.1–100%) even 8 years before death. It is a diagnostic finding from one cohort and does not show that measuring or lowering p-tau181 treats or prevents the disease.
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Diagnostic performance and prediction of clinical progression of plasma phospho-tau181 in the Alzheimer's Disease Neuroimaging Initiative
In more than 1000 people from the Alzheimer's Disease Neuroimaging Initiative, blood p-tau181 was already raised before symptoms in people with amyloid on PET and rose further in mild cognitive impairment and Alzheimer's dementia. It separated Alzheimer's dementia well (AUC 85.3%) but amyloid-positive from amyloid-negative people less well (AUC 76.9%), and higher baseline levels predicted later dementia about as well as the spinal-fluid p-tau181 test. These are group-level results from a research cohort with no stated cut-off, so they do not show that one blood result can diagnose or forecast Alzheimer's in an individual.
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Plasma P-tau181 in Alzheimer's disease: relationship to other biomarkers, differential diagnosis, neuropathology and longitudinal progression to Alzheimer's dementia
In 589 people from three cohorts, levels of a tau protein in blood (P-tau181) were higher at early, symptom-free stages of Alzheimer's and higher again at mild cognitive impairment and dementia. The blood test separated Alzheimer's dementia from other brain diseases with accuracy the authors describe as similar to spinal-fluid testing and tau PET scans (AUC 0.94–0.98), and high levels were associated with later Alzheimer's dementia. The authors conclude it "may be useful in clinical practice and trials"; it is a test, not a treatment, and the record does not report how well it predicts any one person's future.
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CSF biomarkers and incipient Alzheimer disease in patients with mild cognitive impairment
In 750 people with mild cognitive impairment followed for at least two years across 12 centres in Europe and the US, the 271 who went on to be diagnosed with Alzheimer's had, at the start, lower spinal-fluid amyloid-beta 42 and higher total tau and phosphorylated tau than those who did not. The authors say these markers identified incipient Alzheimer's "with good accuracy, but less accurately than reported from single-center studies", and that the amyloid-beta test varied considerably between sites, so they called for standardised lab methods. The study measured prediction only; the values for the two groups overlapped widely, so a single result cannot say for certain what will happen to one person.
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Sex Differences in Cognitive Decline Among US Adults
This pooled analysis found that women had higher baseline cognitive performance but faster cognitive decline than men. It concerns sex differences in cognitive decline and does not test any treatment, cure or prevention for Alzheimer's disease.
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Mini-Mental State Examination (MMSE) for the early detection of dementia in people with mild cognitive impairment (MCI)
This review included 11 studies of 1569 people with mild cognitive impairment to see whether the Mini-Mental State Examination can detect who later develops dementia. It is a review of a screening tool for early detection, not a treatment, cure, or prevention study.
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Updated appropriate use criteria for amyloid and tau PET: A report from the Alzheimer's Association and Society for Nuclear Medicine and Molecular Imaging Workgroup
This workgroup updated appropriate use criteria for amyloid PET and developed criteria for tau PET, rating 17 clinical scenarios. For amyloid PET, seven scenarios were rated appropriate, two uncertain, and eight rarely appropriate; for tau PET, five were appropriate, six uncertain, and six rarely appropriate.
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Hypoglycemic episodes and risk of dementia in older patients with type 2 diabetes mellitus
In older patients with type 2 diabetes, having hypoglycemic episodes severe enough to require hospitalization was linked to a higher risk of later dementia, with risk rising as the number of episodes increased. This is an observational cohort finding about a risk association, not proof that preventing hypoglycemia prevents dementia.
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Plasma p-tau231: a new biomarker for incipient Alzheimer's disease pathology
In this study, a new blood test for p-tau231 was already raised in people with only slight amyloid build-up (the second-lowest of four amyloid-PET bands), before the level at which an amyloid PET scan is called positive; spinal-fluid p-tau217 and blood p-tau181 rose only in higher bands. The authors report that it identified clinical stages of Alzheimer's and neuropathology equally well as blood p-tau181, so its advantage is earlier detection rather than better accuracy. It is a biomarker study comparing groups, not a treatment, and it does not show what a single person's result means.
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Plasma tau in Alzheimer disease
In 1,284 people from two cohorts (ADNI and Sweden's BioFINDER), higher plasma tau went with Alzheimer dementia and with CSF signs of Alzheimer pathology, but the correlations were weak and differed between the cohorts. The authors found "the overlap between normal aging and AD is large, especially in patients without dementia," and concluded the results "do not support plasma tau as an AD biomarker in individual people." In ADNI, higher plasma tau was linked with worse cognition, more atrophy and more hypometabolism over follow-up, but only at the group level.
See all 815 studies in Getting a diagnosis, with filters →
Newest additions on this subject
- The Contribution of Routinely Collected Clinical Data to Dementia Identification in Primary Care: A Cross-Sectional Study
- Beyond “Denial”: Understanding and Responding to Help-Refusal in Dementia
- A Machine Learning-Based Framework for differential screening of Neurodegenerative Dementias using routine clinical data
- Diagnostic accuracy of remote self-administered digital cognitive assessment by clinical diagnosis and Alzheimer's disease PET imaging biomarkers
- Alcohol use disorder accelerates age-related cognitive decline
- Adaptation and Validation of Brief Tablet-Based Cognitive Assessment Tool in Uganda
- Hippocampal surface analysis using discrete Ricci flow and Riemannian metrics for the diagnosis of Alzheimer's disease
- EHR-Enabled Alzheimer’s Disease Care Pathways in Primary Care: Results from a Multisite Implementation Pilot
- Detection and Continuous Monitoring of Memory Dysfunction in Mild Cognitive Impairment and Healthy Aging Through Adaptive Computational Phenotyping
- Data-driven subtypes of Alzheimer's Disease: A multicohort study
All 815 studies in Getting a diagnosis, newest first →
What the library holds on this subject
By review status
| Status | Studies |
|---|---|
| Peer-reviewed | 789 |
| Preprint — not yet peer-reviewed | 24 |
| Report — not peer-reviewed | 1 |
| Conference abstract — not peer-reviewed | 1 |
By strength of evidence
| Rated in our summary | Studies |
|---|---|
| low | 545 |
| moderate | 213 |
| high | 42 |
| not rated | 9 |
| early | 5 |
| null-result | 1 |
Most frequent journals
| Journal | Studies |
|---|---|
| Neurology | 77 |
| The Lancet. Neurology | 33 |
| Brain : a journal of neurology | 32 |
| Archives of neurology | 21 |
| Annals of neurology | 20 |
| Alzheimer's & dementia : the journal of the Alzheimer's Association | 19 |
| JAMA | 17 |
| Alzheimer s & Dementia | 16 |
| Acta neuropathologica | 14 |
| Lancet (London, England) | 13 |
Studies by year published
| Year | Studies | Bar |
|---|---|---|
| 2026 | 53 | |
| 2025 | 180 | |
| 2024 | 9 | |
| 2023 | 6 | |
| 2022 | 6 | |
| 2021 | 13 | |
| 2020 | 14 | |
| 2019 | 19 | |
| 2018 | 16 | |
| 2017 | 26 | |
| 2016 | 21 | |
| 2015 | 23 | |
| 2014 | 26 | |
| 2013 | 26 | |
| 2012 | 29 | |
| 2011 | 32 | |
| 2010 | 29 | |
| 2009 | 25 | |
| 2008 | 24 | |
| 2007 | 21 | |
| 2006 | 23 | |
| 2005 | 21 | |
| 2004 | 16 | |
| 2003 | 14 | |
| 2002 | 15 | |
| 2001 | 17 | |
| 2000 | 16 | |
| 1999 | 10 | |
| 1998 | 9 | |
| 1997 | 12 | |
| 1996 | 9 | |
| 1995 | 6 | |
| 1994 | 3 | |
| 1993 | 3 | |
| 1992 | 9 | |
| 1991 | 7 | |
| 1990 | 3 | |
| 1989 | 1 | |
| 1988 | 3 | |
| 1987 | 1 | |
| 1986 | 4 | |
| 1985 | 2 | |
| 1984 | 2 | |
| 1983 | 4 | |
| 1982 | 4 | |
| 1980 | 2 | |
| 1976 | 1 |
Counts the 815 studies with a usable publication date. The library is a large sample of published work, not a complete index, so these counts describe the library, not the whole field.
Other subjects in the library
- Biomarkers
- Clinical trials
- Prevention and risk
- Caregiving
- How common it is
- Costs and economics
- Genetics
- Laboratory science
- Disease mechanisms
- Vascular contributions
- Prevention trials
- Clinical safety
- Health systems and care delivery
- End-of-life care
- Risk factors
- Digital health tools
- Treatments
- Disparities
- Mild cognitive impairment
- Risk genes beyond APOE
- Brain scans and imaging
- TREM2 and immune genetics
- Cognitive tests and assessment
- Lewy body dementia
- Down syndrome and Alzheimer's
- Long-term cohort studies
- Inflammation and the immune system
- Tau biomarkers
- Brain tissue and pathology
- Drug development
- Hippocampus size on brain scans