Each study has a usefulness score out of 100 (rubric version 4.0). Tap a score to see what makes it up.
Highest usefulness score first. Studies without a score come last.
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We found 32 studies with burden models and 24 depression and mental health models.
Why it matters
This review of 32 studies found that patient behavioral problems, caregiver coping, personality traits and competence are the most consistent factors linked to caregiver burden, depression and mental health. It is about supporting caregivers rather than treating, curing or preventing Alzheimer's disease itself.
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Studies of long-term cognitive change should account for the potential effects of education on the outcome, since some studies have demonstrated an association of education with dementia risk.
Why it matters
This study measured change in cognitive test performance over 20 years and considered how education and study dropout might affect the results. It is observational and does not test any treatment or prevention for dementia.
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63/100
In a large IRBD cohort diagnosed in a tertiary referal sleep center, prolonged follow-up indicated that the majority of patients are eventually diagnosed with the synucleinopathies PD, DLB and less frequently MSA.
Why it matters
This study found that most patients with idiopathic REM sleep behavior disorder eventually developed a synucleinopathy such as dementia with Lewy bodies, Parkinson disease or multiple system atrophy. It describes a prodromal period for these conditions, but does not test treatment, cure or prevention for Alzheimer's disease.
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63/100
Some prior studies showed lower circulating BDNF in persons with Alzheimer disease (AD) compared with control participants; however, it remains uncertain whether reduced levels precede dementia onset.
Why it matters
In the Framingham Heart Study, people with higher blood levels of BDNF (a protein that supports brain cells), measured before any dementia, were less likely to develop it later: those in the top fifth had less than half the risk of dementia and of Alzheimer's compared with the bottom fifth (hazard ratios 0.49 and 0.46), based on 140 dementia cases, 117 of them Alzheimer's. Genes that influence BDNF were not linked to Alzheimer's risk, and the study measured an association only, so it does not show that raising BDNF would lower anyone's risk.
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Evidence strongly supports the important role of insulin resistance in cognitive decline and dementia and suggests that insulin sensitizers may protect against cognitive decline in diabetic and pre-diabetic individuals.
Why it matters
In this study of 365 older people with diabetes, metformin use was linked to lower odds of cognitive impairment over 4 years, with a significant trend across duration of use. This is an observational association, so it does not show that metformin prevents or treats Alzheimer's disease.
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There is substantial neuropsychological decline in schizophrenia from the premorbid to the postonset period, but the extent and developmental progression of decline varies across mental functions.
Why it matters
In this longitudinal cohort, individuals with schizophrenia showed declines in IQ and in mental functions such as processing speed, learning, executive function and motor function, with little evidence of decline in verbal abilities or delayed memory. This study concerns schizophrenia, not Alzheimer's disease, and does not test any treatment for Alzheimer's disease.
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Internet interventions for informal dementia caregivers may improve caregiver well-being.
Why it matters
This review of Internet-based support for dementia caregivers found the overall level of evidence was low, with wide differences in intervention type, dose, and duration. It reported that such interventions can improve aspects of caregiver well-being, such as confidence, depression, and self-efficacy, if they have multiple components and are tailored to the individual.
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UK care home residents are often poorly served by existing healthcare arrangements.
Why it matters
This cohort study describes the health status and healthcare resource use of UK care home residents over 180 days. It is a descriptive study of care home residents, not a study of treating, curing, or preventing Alzheimer's disease.
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Affective disorders appear to be associated with an increased risk of developing dementia, and one that is dependent on clinical and demographic variables.
Why it matters
This review of 51 studies found that people with depression, and possibly bipolar disorder, had a higher risk of developing dementia. It suggests depression may be both an early sign and a risk factor for dementia, but it does not show that treating depression prevents dementia.
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The past and ongoing increase in midlife obesity prevalence will contribute significantly to the future prevalence of dementia and public health measures to reduce midlife obesity are simultaneously primary prevention measures to reduce the risk of dementia.
Why it matters
This meta-analysis found that midlife obesity increases later dementia risk, and that including obesity in forecasts raises projected dementia numbers in the United States and China. The authors conclude that reducing midlife obesity would also be a primary prevention measure for dementia.
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Acceleration in WMH burden, a common indicator of cerebrovascular disease in the elderly, is a pathologic change that emerges early in the presymptomatic phase leading to MCI.
Why it matters
In 181 older adults who started out cognitively normal and had brain MRI every year for up to 19.6 years, the growth of white matter hyperintensities, which the study calls "a common indicator of cerebrovascular pathology," sped up on average about 10.6 years before mild cognitive impairment, while enlargement of the fluid-filled ventricles sped up only about 3.7 years before. Among 63 people who developed MCI and later had autopsy, only 28.5% had Alzheimer's alone and 24% had Alzheimer's plus significant vascular disease. This suggests blood-vessel-related brain changes start early and often occur alongside Alzheimer's, though it shows timing, not cause.
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There is evidence of geographical variation in rates of dementia in affluent countries at a variety of geographical scales.
Why it matters
This meta-analysis found that rural living is associated with an increased risk of Alzheimer's disease, with a suggestion that early life rural living further increases this risk. It identifies a possible socio-environmental contribution to dementia but does not test any treatment or prevention.
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Treatment with celecoxib or naproxen did not improve depressive symptoms over time compared with placebo.
Why it matters
In this randomized, placebo-controlled trial of 2,528 cognitively normal volunteers aged 70 and older with a family history of Alzheimer-like dementia, celecoxib and naproxen did not benefit depressive symptoms. The study addresses depressive symptoms in this population, not the treatment, cure, or prevention of Alzheimer's disease itself.
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Lower education was associated with a greater risk for dementia in many but not all studies.
Why it matters
This systematic review of 71 studies found that 51 studies (58%) reported significant effects of lower education on risk for dementia while 37 studies (42%) reported no significant relationship, and that more years of education did not uniformly attenuate the risk. The authors conclude that the relationship with dementia was more consistent when years of education reflected cognitive capacity, so the link between education and dementia risk is not uniform.
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High BP accelerates gait slowing in well-functioning older adults over a long period of time, even for those who control their BP or develop hypertension later in life.
Why it matters
In well-functioning older adults followed for 18 years, higher systolic blood pressure was linked to faster decline in walking speed. This connects blood pressure to a mobility change over time, not directly to treating, curing, or preventing Alzheimer's disease.
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We reported the interim findings of a randomized controlled trial (RCT) to examine the effects of a mind body physical exercise (Tai Chi) on cognitive function in Chinese subjects at risk of cognitive decline.
Why it matters
In this interim report of a randomised trial in 389 Chinese older people at risk of cognitive decline, both the Tai Chi group and the stretching control group improved on global cognitive function, delayed recall and subjective cognitive complaints. The authors describe these as interim findings and say longer observation is needed, so no conclusion can be drawn yet about preventing dementia.
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Among 1,969 subjects without dementia, 329 subjects had MCI, with a prevalence of 16.0% (95% confidence interval [CI] 14.4-17.5) for any MCI, 11.1% (95% CI 9.8-12.3) for amnestic MCI, and 4.9% (95% CI 4.0-5.8) for nonamnestic MCI.
Why it matters
In a random sample of Olmsted County, Minnesota, residents aged 70 to 89 who did not have dementia, 329 of 1,969 people (16.0%) had mild cognitive impairment, most often the memory-led "amnestic" type (11.1%). MCI was more common with older age, with fewer years of education, in people who never married, in people with an APOE ε3ε4 or ε4ε4 genotype, and in men, whose odds were 1.54 times higher after adjusting for age and education. The authors only suggest that women may instead move from normal thinking to dementia later and more abruptly; this study counts who has MCI at one point in time and does not test any treatment or prevention.
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Severe psoriasis is associated with an increased risk of death from a variety of causes, with cardiovascular death being the most common aetiology.
Why it matters
In this cohort, patients with severe psoriasis were at increased risk of death from dementia (hazard ratio 3.64) among other causes. The study describes an association between severe psoriasis and cause-specific mortality, not a treatment or prevention for Alzheimer's disease.
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Incidence of all-cause dementia is very high in people aged 90 years and older and continues to increase exponentially with age in both men and women.
Why it matters
In people aged 90 and older, the incidence of all-cause dementia was very high and continued to increase exponentially with age, with similar rates in men and women. The authors say these results foretell a growing public health burden of dementia in an aging population, which is about planning for care rather than treatment or prevention.
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Higher baseline body mass index (BMI) and slower declining BMI in late life are associated with a reduced risk of dementia, suggesting that low BMI or a faster decline in BMI in late life may be preclinical indicators of an underlying dementing illness, especially for those who were initially overweight or obese.
Why it matters
In this cohort of 1836 Japanese Americans, higher baseline body mass index and slower decline in body mass index were linked to reduced risk of dementia. These are observational associations and do not show that weight change prevents or treats Alzheimer's disease.
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Folic acid supplements may sometimes therefore include vitamin B12 supplements with simultaneous administration of vitamin B12.Lesser degrees of folate inadequacy are associated with high blood levels of the amino acid homocysteine which has been linked with the risk of arterial disease, dementia and Alzheimer's disease.
Why it matters
In one trial of healthy elderly people with high homocysteine levels, 800 mcg/day folic acid over three years was associated with significant benefit in global functioning, memory storage, and information-processing speed. In a pilot trial of people with Alzheimer's disease, the overall response to cholinesterase inhibitors significantly improved with folic acid.
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Consistent with trials evaluating other cholinesterase inhibitors, rivastigmine did not provide consistent efficacy in probable VaD.
Why it matters
In this 24-week trial of 710 people with probable vascular dementia, rivastigmine capsules beat placebo on three cognitive tests but not on other outcomes, and the authors concluded it "did not provide consistent efficacy." The cognitive benefit came from patients aged 75 and older, who the authors assumed were more likely to also have Alzheimer's pathology; younger patients showed no benefit and slight rises in blood pressure, strokes and deaths. The authors read this as support for the idea that any cholinergic deficit in vascular dementia reflects co-existing Alzheimer's disease.
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Very mild bvFTD targets a specific subset of frontal and insular regions.
Why it matters
In people with very mild behavioral variant frontotemporal dementia, the earliest shrinkage appeared in frontal and related brain regions. This describes where damage begins in this disease and does not test any treatment or cure.
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MCI occurs often in this elderly Italian cohort and is associated with greater risk of AD, but only when the impairment involves the memory domain.
Why it matters
In 745 people aged 65 and older from one Italian town, followed for about 4 years, mild cognitive impairment (MCI) that affected memory was linked to roughly 6 times the risk of Alzheimer's dementia (adjusted risk 5.92) compared with normal thinking, while MCI that did not affect memory showed no link to dementia. Even so, about one-third of people with memory-affecting MCI did not develop dementia. MCI was common: 7.7% of the population had it, and it was more frequent with older age and less education.
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As predicted by the cognitive reserve hypothesis, higher education delays the onset of accelerated cognitive decline; once it begins it is more rapid in persons with more education.
Why it matters
In this longitudinal study, each additional year of formal education delayed the start of accelerated memory decline by 0.21 years, but after that point memory declined faster for each additional year of education. This supports the cognitive reserve hypothesis but does not show that education prevents Alzheimer's disease.
From across this topic
10 of the 7,967 studies in this topic, 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.
- Improvement of Cognitive Function after Computer-Based Cognitive Training in Early Stage of Alzheimer's Dementia
- Treatment of Mania in Dementia With Electroconvulsive Therapy
- Family perceptions of end-of-life care for long-term care residents with dementia: differences between the United States and the Netherlands
- HIV encephalitis, proviral load and dementia in drug users and homosexuals with AIDS. Effect of neocortical involvement
- Computerised cognitive training for maintaining cognitive function in cognitively healthy people in late life
- Ethnic differences in the prevalence and pattern of dementia-related behaviors
- Effects of education and race on cognitive decline: An integrative study of generalizability versus study-specific results
- Association Between Acute Myocardial Infarction and Cognition
- Brain plasticity and motor practice in cognitive aging
- Rapid Acting Insulin Use and Persistence among Elderly Type 2 Diabetes Patients Adding RAI to Oral Antidiabetes Drug Regimens