A clinical trial is a research study that tests a new medicine, device or way of giving care in people. Every dementia medicine we have today was tested this way first. For example, the main study of the Alzheimer's drug lecanemab enrolled 1,795 volunteers.12
Joining a trial is a personal choice. It can give you access to close medical attention and a chance to help future families. It also takes time and has some risks. This page explains what trials involve, how volunteers are protected, and how to find one.
Key points
- Trials test whether something new is safe and whether it works. You may get the new treatment or a placebo (a look-alike with no medicine), and you may not benefit.1,4
- Volunteers are protected by informed consent, review by an independent ethics board, and ongoing safety checks. You can leave a study at any time.1,2,4
- You can search for studies on ClinicalTrials.gov, through the Alzheimer's Association's free TrialMatch service (800-272-3900), or by contacting an Alzheimer's Disease Research Center.3,6,7
- Many dementia studies also need healthy volunteers and caregivers, not only people with memory loss.6
- Asian Americans are underrepresented in dementia research. The CARE registry connects Asian American, Native Hawaiian and Pacific Islander adults with studies in nine languages.9,10
What a clinical trial is
Research that involves people is called clinical research. A clinical trial is one kind. It tests whether a way to prevent, detect or treat a disease is safe and works.1 Other studies only watch people over time, such as yearly memory tests and brain scans, without giving any treatment.1
Every trial follows a written plan called a protocol. It spells out what will be done, how, and why.5 Each study also has rules about who can join, such as age, stage of memory loss, other health problems and medicines.5
Dementia studies test many kinds of things:6
- New drugs to treat the disease or its symptoms
- New ways to diagnose it
- Ways to prevent it
- Non-drug approaches to care and support
To see which treatments are being tested right now, read new treatments being tested.
The phases of a drug trial
New drugs go through several steps, or phases. Each one is larger than the last.1
| Phase | About how many people | Main question |
|---|---|---|
| Phase 1 | 20 to 80 | Is it safe? What side effects does it cause? |
| Phase 2 | 100 to 300 | Does it seem to work? Is it still safe? |
| Phase 3 | 1,000 to 3,000 | Does it work better than a placebo or current care? |
| Phase 4 | Many, after FDA approval | How safe and useful is it in everyday life? |
Source for the table: NIH.1
Phase 3 trials often decide whether the FDA approves a drug. Lecanemab (Leqembi) got full approval in July 2023 after its phase 3 study.12 Learn more on our lecanemab page.
What being in a trial is like
Every study is different, but these parts are common.
Placebo and chance. In many trials, a computer assigns each person to a group by chance, a bit like flipping a coin. This is called randomization. It keeps the comparison fair.1 One group may get a placebo. You will be told before you join if a placebo is used.1
Blinding. Often neither you nor the research team knows which group you are in. This is called double-blind. The team can find out if it is needed for your safety.1
Visits and tests. Trials often need more visits and tests than regular care.1 Dementia drug trials may include memory tests, blood draws, brain scans (MRI or PET), and sometimes a spinal fluid test. See our pages on brain scans and spinal fluid tests.
A study partner. Alzheimer's studies usually ask each volunteer to bring a study partner, even prevention studies for people without memory problems. This is often a spouse, adult child or close friend who knows the person well.11 The partner answers questions about memory and daily life and may come to visits. Some people find it hard to find a partner, especially one who works or cares for others. Researchers have suggested options like video visits to make the role easier.11 Ask the study team what the partner role involves before you agree.
Possible benefits and risks
Possible benefits
Some anti-amyloid drugs cause brain swelling or small bleeds, called ARIA. Trials of these drugs use regular MRI scans to watch for it. Read more about ARIA.
If something feels wrong during a study, call the study team right away. Their phone number is on your consent papers.4
Call 911 for sudden weakness on one side, trouble speaking, a drooping face, a seizure, or trouble breathing. Tell the emergency team that the person is in a clinical trial and bring the study contact card if you have one.
Do not stop or change any regular medicine to join or stay in a study without talking with your own doctor first.
How volunteers are protected
There are several layers of protection for people in studies.
Informed consent. Before you join, the team must explain the study's purpose, how long it lasts, what will happen, the risks and possible benefits, and other treatment choices.4 Consent is not just one signature. It is an ongoing process. You can take the papers home, ask questions and talk with family before you decide.4 The team must tell you about new information that could change your mind.2
The explanation has to be in words you can understand.4 If English is not your first language, ask whether the consent form and visits are available in your language, or whether a medical interpreter can help.
Independent review. An Institutional Review Board (IRB) is a committee of doctors, statisticians and community members. It checks that a study is ethical and that risks are reasonable.5 A trial must have IRB review if it tests an FDA-regulated product or is paid for by the federal government.5 An independent panel also keeps watching the study while it runs.2 Ask whether your study has IRB approval.1
Your rights. Joining is always voluntary. You can say no, or leave at any time, without losing care or benefits you would normally get.4 Your private information must be kept confidential.2 A consent form can never ask you to give up your legal rights.4
When memory loss affects decisions. As dementia progresses, a person may find it harder to weigh a study's risks and benefits. Ask the study team how they handle consent if this happens, and who can help decide. It helps to talk about research wishes early and write them down. See advance directives.
How to find a trial
You do not need a doctor's referral to look for studies. But talk with your doctor before you join any study.3
- ClinicalTrials.gov. This free government database lists studies in the United States and around the world. Each listing shows who can join, where the study is and who to call.3 You can search for "Alzheimer's" or "dementia" plus your city or zip code. A listing does not mean the government has checked or approved the study.3
- Alzheimer's Association TrialMatch. This free service asks about 10 questions about you or the person you care for. Then it shows studies that may fit. You contact the researchers yourself if you want to. Your information stays private unless you choose to share it. Call 800-272-3900 for help, or visit alz.org/trialmatch.6
- Alzheimer's Disease Research Centers (ADRCs). The National Institute on Aging funds 37 of these centers across the country.7 They work on better diagnosis and care and on ways to treat or prevent dementia. Each has its own research focus and enrollment process.7 There is not one in every state, so you may need to look at a nearby state.
- Research registries. ResearchMatch is a free, NIH-funded registry that links volunteers with researchers.3 Joining a registry does not sign you up for a study. You are only contacted when a study may fit.
- Your own doctors. Memory clinics and neurologists often know about local studies. See which specialist to see.
Asian Americans and dementia research
Asian American, Native Hawaiian and Pacific Islander older adults are among the fastest-growing groups in the United States. But they are underrepresented in research on aging, dementia and caregiving.10 Studies that focus on these communities make up less than 1% of NIH-supported clinical research.9
This matters. If a group is missing from studies, doctors know less about how well a drug works for them, how safe it is, or how well memory tests work in their language and culture.
The CARE registry (Collaborative Approach for AANHPI Research and Education) was built to help close this gap. Adults 18 and older who identify as Asian, Asian American, Native Hawaiian or Pacific Islander and live in the United States can join.9 It works in English, Cantonese, Mandarin, Hindi, Japanese, Korean, Samoan, Tagalog and Vietnamese.9 You can sign up online or by calling or texting (669) 256-2609.9
Joining CARE does not commit you to any study. You are only contacted about studies you may qualify for, and you always decide.9 By late 2024, more than 10,000 adults had joined. About half had limited English, and about 4 in 5 had never been in a research study before.10 The registry says more than 18,000 people have now enrolled.9
Costs and payment
Ask about money before you join. Questions to ask include whether you will pay for any tests or study drugs, what your insurance covers, and whether travel costs are paid.1 The consent form should say if there are any extra costs to you.4 Also ask whether the study offers any payment for your time.
Medicare. Medicare covers some costs of clinical research studies, such as office visits and tests. After the Part B deductible, you usually pay 20% of the Medicare-approved amount.8 Ask the study team which costs the study pays and which are billed to your insurance.
Questions to ask before joining
About the study
- What is the study trying to learn? Which phase is it?
- Is there a placebo? What are my chances of getting it?
- How long does it last? How many visits, and how long is each?
- Has an IRB approved it? How is safety watched?1
About risks and care
- What are the known risks and side effects?
- Who do we call if there is a problem at night or on a weekend?
- Can I keep seeing my own doctor and taking my usual medicines?
- What happens when the study ends? Can I keep getting the treatment?
About the study partner and daily life
- What does the study partner need to do? Can some visits be by phone or video?
- Is the consent form available in my language? Is there an interpreter?
- Will travel, parking or meals be paid?
- Will I learn my own test results, such as amyloid or APOE gene results?
For caregivers
Trials can add appointments and paperwork to an already full life. Keep visit dates and study contacts in one place, like a memory notebook. Share the work with family if you can. See our caregiver support pages and caregiver training programs.
If caregiving stress ever leads to thoughts of suicide, call or text 988 at any time. In an emergency, call 911.
Sources
- National Institutes of Health. NIH clinical research trials and you: the basics. NIH, 2025. NIH
- National Institutes of Health. Guiding principles for ethical research. NIH, 2025. NIH
- National Institutes of Health. Finding a clinical trial. NIH, 2025. NIH
- U.S. Food and Drug Administration. Informed consent for clinical trials. FDA. FDA
- MedlinePlus. Clinical trials. National Library of Medicine. MedlinePlus
- Alzheimer's Association. TrialMatch: find clinical trials. Alzheimer's Association, 2026. alz.org
- National Alzheimer's Coordinating Center. ADRC program. NACC, 2026. NACC
- Medicare.gov. Clinical research study coverage. Centers for Medicare & Medicaid Services, 2026. Medicare.gov
- CARE Registry. About CARE. University of California, San Francisco, 2026. CARE Registry
- Grill JD, Tsoh JY, et al. Increasing representation of Asian American, Native Hawaiian, and Pacific Islander communities in aging, dementia, and caregiving research: an update from the CARE registry. Alzheimers Dement, 2025. eScholarship
- Largent EA, et al. You've got a friend in me: how cognitively unimpaired older adults select a study partner to participate with them in Alzheimer's disease research. J Alzheimers Dis, 2022. DOI
- U.S. Food and Drug Administration. FDA converts novel Alzheimer's disease treatment to traditional approval. FDA, 2023. FDA
Education only. This page is general information written from the sources listed. It is not medical, legal or financial advice and does not replace a doctor, therapist or lawyer who knows your situation. How we write and check pages.