An Update on Alzheimer’s Disease

June is Alzheimer’s and Brain Awareness Month. An estimated 7.2 million Americans age 65 and older have Alzheimer’s dementia as of 2025. Here’s an update on what is currently known about Alzheimer’s disease, including symptoms, treatments and research efforts to prevent it.

What Is Alzheimer’s Disease?

Alzheimer’s is the most common cause of dementia in older adults. Dementia is defined as the loss of cognitive functioning and behavioral abilities to the point of interfering with a person’s daily activities.

Symptoms of Alzheimer’s

While symptoms of Alzheimer’s can vary, for many the early stages involve a decline in non-memory aspects of cognition, such as word-finding, vision/spatial issues and impaired reasoning or judgment. In mild Alzheimer’s disease, symptoms include:

Greater memory loss
Wandering and getting lost
Problems handling money or paying bills
Repeating questions
Longer times to complete routine tasks
Behavioral and personality changes
Losing track of time
Impaired judgment or decision-making
Misplacing things and unable to retrace steps to find them
Vision problems that make it hard to judge distance or determine color or contrast

It is often in the mild stage that people are diagnosed with Alzheimer’s. It is believed that damage to the brain starts 20 or more years before memory and other cognitive problems appear, making it difficult to prevent and treat the disease.

How Does Alzheimer’s Disease Change the Brain?

Abnormal clumps, called “amyloid plaques,” and tangled bundles of fibers, called “neurofibrillary,” or “tau” tangles, are present in the brain tissue of a person with Alzheimer’s. Another feature is the loss of connections between nerve cells (neurons) in the brain. Normal neurons transmit messages between different parts of the brain and from the brain to muscles and organs in the body.

When abnormal deposits of proteins form amyloid plaques and tau tangles throughout the brain, once-healthy neurons stop functioning, lose connections with other neurons and die. The initial damage appears to take place in the hippocampus, an area of the brain essential in forming memories. As neurons die, brain tissue in affected areas begins to shrink. By the final stage of Alzheimer’s, the damage is widespread and brain tissue has shrunk significantly.

Symptoms of Mild Cognitive Impairment (MCI)

Some people with memory problems have “mild cognitive impairment” (MCI). People with MCI may have more memory problems than normal for their age, but the symptoms do not interfere with their daily lives. Older people with MCI are at greater risk for developing Alzheimer’s, but not all of them do; some may actually go back to normal cognition.

Diagnosing Alzheimer’s

Physicians, neuropsychologists, geriatric psychiatrists and other specialists use a variety of tools and approaches to make an accurate diagnosis of Alzheimer’s and what’s causing it. They look at a patient’s:

Medical history
Mental cognitive status test results
Physical exam and diagnostic test results
Brain imaging results
Neurological exam results

Please note that there is no proven accuracy in dementia home screening tests. A patient must be screened and diagnosed only by qualified healthcare professionals at designated medical institutions.

Treating Alzheimer’s

Current treatments for Alzheimer’s disease focus on helping individuals maintain mental function, manage behavioral symptoms and slow the progression of symptoms. Medications may be prescribed depending on the stage of the disease, and while they do not cure Alzheimer’s, they can offer some improvement in quality of life.

FDA-Approved Medications to Manage Symptoms

Several medications are currently approved by the U.S. Food and Drug Administration (FDA) to treat symptoms of Alzheimer’s disease. These include:

Donepezil: A cholinesterase inhibitor used for all stages of Alzheimer’s disease. It works by preventing the breakdown of acetylcholine in the brain and may cause side effects like nausea, insomnia, muscle cramps and weight loss.
Galantamine: Another cholinesterase inhibitor, used to treat mild to moderate Alzheimer’s. It also stimulates the brain’s nicotinic receptors to release more acetylcholine. Side effects can include dizziness, decreased appetite, and digestive upset.
Benzgalantamine: A form of galantamine developed to reduce digestive side effects while offering similar cognitive benefits.
Rivastigmine: A cholinesterase inhibitor used for mild to severe Alzheimer’s. It targets both acetylcholine and butyrylcholine and is available in oral and transdermal patch forms. Common side effects include nausea, vomiting and muscle weakness.
Memantine: An NMDA antagonist used to treat moderate to severe Alzheimer’s. It helps regulate the activity of glutamate, a chemical involved in learning and memory. Side effects may include confusion, dizziness and constipation.
Memantine combined with Donepezil: This combination therapy is approved for moderate to severe Alzheimer’s. It offers dual-action support by regulating glutamate and preserving acetylcholine. Possible side effects include headache, nausea and small bruising under the skin (ecchymosis).
Brexpiprazole: An atypical antipsychotic recently approved to treat agitation associated with Alzheimer’s disease. While it does not address memory or cognitive symptoms, it may help with behavioral disturbances. Side effects can include dizziness, cold-like symptoms and elevated blood sugar.

FDA-Approved Medications to Treat Alzheimer’s Disease Progression

Recent advances have introduced disease-modifying immunotherapies designed to slow the progression of Alzheimer’s by targeting beta-amyloid plaques in the brain:

Lecanemab: Another beta-amyloid-targeting drug, approved to treat individuals with MCI or mild Alzheimer’s. It may help reduce plaque buildup and slow disease progression. Side effects can include brain swelling, bleeding, headache and fatigue.
Donanemab: Similar to lecanemab, this drug helps clear beta-amyloid from the brain and is used in early-stage Alzheimer’s. It may cause side effects such as brain swelling, confusion, vision changes or seizures.

Approaching Memory Concerns in Others

If you notice changes in the thinking, behavior or memory of friends or family, here’s a guide to help you assess the situation:

What thinking, behavior or memory changes do you see? What is the person doing or not doing that is unusual?
What other health conditions does this person have?
Learn more about the 10 early signs of Alzheimer’s and see if you notice any of these signs in a person.
Who else has noticed these changes among the person’s friends or family? And what are these changes?
Determine if it’s best to discuss your concerns with the person one-on-one, or you may need to include a trusted friend or family member.
Set the best time and place to have the conversation.
Open up about the changes you’ve noticed in the person. You can say something like: “I noticed you [specific example] and it worried me. Has anything else like that happened before?”
Offer to take the person to a doctor. “The sooner we know what’s causing these problems, the sooner we can address it.” “Let’s see if the doctor can help us figure out what’s going on.”
Have as much conversation as possible. Note the following:
When and where the discussion happened
What worked well and what didn’t?
What was the result?
What can be done differently next time?
Ask for information and support from the Alzheimer’s Association via 800-272-3900.

Research and Clinical Trials

Besides treating Alzheimer’s symptoms, scientists are looking at ways to address underlying disease processes. A study published in June 2018, funded by the National Institute of Health, suggested that certain viruses may be linked to Alzheimer’s disease biology.

To help advance knowledge of the disease, including ways to help diagnose, treat and even prevent Alzheimer’s, ongoing clinical trials are being conducted that monitor healthy individuals, those with early-onset Alzheimer’s and those at risk for developing Alzheimer’s. To learn more about clinical trials for Alzheimer’s disease, contact the National Institute on Aging.

The following registries are an opportunity for people to sign up for Alzheimer’s disease prevention trials:

If you know someone who may be at risk, click here to locate a healthcare provider for brain and neurological conditions.