Some dementia cases may be linked to treatable microorganism infections in the brain.

Memory disorders disrupt the brain's ability to make, store, or recall memories

These disorders stem from reversible issues like vitamin deficiencies or irreversible causes such as stroke or dementia. Only one type of dementia—familial Alzheimer’s disease—is directly inherited and accounts for about 20% of Alzheimer’s cases.

Gut microbiome experiments involving transfers of gut microbes from depressed people to rodents indicate that the rodents may then display depression-like symptoms.

Trillions of bacteria, viruses, fungi, protists, and archaea live in our guts, producing a wide range of molecules, hormones, and more—underscoring the immune system's pivotal role in the microbiota-gut-brain axis.

Cryptococcus neoformans, a growing threat, causes infections in the brain and lungs

This inhalable, microscopic pathogen is found worldwide. It rarely causes illness, but it can take root in those with compromised immune systems, including people with advanced HIV/AIDS. Symptoms of cryptococcal infection—such as a stiff neck, vomiting, and confusion—can begin weeks or months after breathing in spores, though sometimes symptoms won’t appear for years. There are no known cases of transmission between people or between people and animals.

Neurogeneration is the process underlying dementia, but it may happen for myriad reasons and its triggers are under investigation.

Why vascular dementia develops

This type of dementia, the second most common form after Alzheimer's, develops due to microscopic bleeds and blood vessel blockages in the brain. The condition isn't curable but medications to help with blood clotting and high blood pressure are part of a suite of interventions designed to minimize damage to the brain.

"Plaques" and "tangles" are top potential causes of Alzheimer's—but questions remain

The exact causes of Alzheimer's—and how to treat it—continue to be the subject of intense research. Two leading factors are amyloid beta plaques and tau protein tangles, which effectively pile up in the brain and interfere with neurons and cause cell death, which manifests as memory loss and other symptoms.

Long-term memory issues among West Nile survivors may be from the body's immune response, not the viral infection.

Alzheimer's brain changes may begin years before symptoms appear.

Ultraprocessed foods are linked with a 58% elevated risk of developing dementia.

Untreated hearing loss is linked with dementia risk

Hearing loss does not cause dementia, but it does increase the risk of developing dementia and research suggests that people who wear hearing aids for age-related hearing loss also maintain better brain function than those who don't.

Researchers are exploring neural links between Alzheimer's and autism

Recent DNA sequencing and molecular biology studies suggest that similarities in genes, neural circuitry and patterns of disease warrant further exploration to potentially better understand both conditions and how to treat them. (Some users may encounter a paywall.)

Supplements ahead of exertional heatstroke helped protect mice against brain damage

In the lab, mice dosed with probiotics prior to inducing exertional heatstroke, had better cognitive outcomes. This evidence underscores the links between the gut microbiome and the brain, at least in rodents.

In 2026, University of Cambridge researchers reported that a group of gut bacteria called CAG-170 may be a key marker of good health, occurring far more often in healthy individuals and less commonly in people with chronic diseases.

Untreated malaria can lead to blocked blood vessels in the brain, coma, and organ failure.

There are two FDA-approved blood tests that may detect early Alzheimer's disease

Yet the tests are only recommended for those who have symptoms of dementia, and are not definitive on their own. False positives are a concern with these new tests, which detect biomarkers that may indicate the presence of brain proteins linked to the disease. This podcast explores the state of research on the disease and concerns about regulators taking jobs at pharmaceutical and biotech companies, which may influence their approach to approvals. It also dives into an investigation about the data underpinning one experimental Alzheimer's drug.

Brain training game creates long-lasting changes in the brain that may help protect against dementia.

1440: Everything you need to know about Alzheimer's

What is Alzheimer's, and is it different from dementia? In short, yes—Alzheimer's is a specific brain disease that falls under the umbrella of dementia. However it is the most prevalent form of the condition, accounting for 60 to 80% of reported dementia cases.

Can the gut microbiome drive addiction?

New research suggests an imbalance of gut microorganisms may influence the likelihood of addiction and addictive behaviors by increasing the severity of withdrawal symptoms, triggering brain inflammation in regions of impulse control, and more.

Alzheimer's disease is the leading cause of dementia and risks rise after age 65

Read this primer about Alzheimer's disease and learn what factors increase the risk of this form of dementia, including genetics, being a woman, and health conditions, including high blood pressure.

How reading and writing can lower dementia risk by almost 40%

Research published in 2026 that tracked almost 2,000 older adults for an average of nearly eight years suggests that lifelong exposure to intellectual stimulation, such as learning a language, reading, and writing, can lower dementia risk by as much as 40%.

Visualize the difference between a healthy brain and one with Alzheimer's.

The brain has three main parts—the cerebrum, brain stem, and cerebellum—each combining to control the entirety of the body's operations. Alzheimer's progressively deteriorates the circuitry in these structures, resulting in what we see as the symptoms of the disease.

Face and neck massages improve the removal of brain cell waste products in mice

A study identified that massaging mice and monkeys' faces and necks enhanced the flow of cerebrospinal fluid. Because CSF has been shown to flush out proteins linked to Alzheimer's and Parkinson's, the research hints at non-invasive treatments to reduce the severity of these diseases.

An analysis of ancient texts found that dementia was rare in ancient Greece.

The first identification of Alzheimer's was made in 1906.

Bacteria in our intestine influence the brain via the gut-brain axis.

Alzheimer's can cause significant brain shrinkage in the affected brain regions, including the hippocampus.

There are up to 100 trillion microbes in the gut, and maintaining the relative balance in this ecosystem is important for our health.

How do 'dementia villages' work?

The goal of good dementia care is to preserve a patient's quality of life as the incurable disease progresses, maximizing their ability to lead normal lives and maintain their health and dignity. Dementia villages are small neighborhoods built for people with severe dementia, with typical neighborhood haunts like salons or grocery stores staffed by people trained in dementia care, helping residents maintain a sense of autonomy and connection.

Scientists are reevaluating the causes of Alzheimer's beyond the amyloid hypothesis after numerous experimental drugs designed to target that theory have failed.

Researchers use the brain's ability to edit memories to explore memory deletion

Scientists have successfully implanted false memories in mice after studying how the editing process works in the brain. Beyond potentially deleting memories in those with PTSD, upcoming research may allow clinicians to forecast the onset of neurodegenerative diseases.

Can your identity be preserved amid dementia?

Memory loss associated with progressive dementia raises questions about whether a person's identity can be maintained during the disease's progression. One outlook suggests we define ourselves by our social relationships—offering a potentially more humane approach to caring for those with dementia.

A dignified later life made possible through dementia villages

Dementia villages are specially designed residential communities tailored for individuals with dementia. These environments offer residents a safe, familiar, and stimulating atmosphere that resembles normal daily life—promoting greater independence, social interaction, and quality of life while discreetly integrating necessary care and support from trained professionals.

How the microbiome affects your health

The gut microbiome is so influential to overall human health that some researchers consider it a separate organ. Its conditions, influenced by environmental and lifestyle factors such as medication and exercise, contribute to immunity, metabolism, inflammation, medical treatment efficacy, brain development and function, and the development of disorders and diseases, including asthma, depression, inflammatory bowel disease, and Alzheimer's.