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Frequently Asked Questions (FAQs)

​Choosing to participate in a clinical trial or research study is an important decision.  Before you or your loved one decide to participate in research, you need to learn what it's like to be in a trial and describe the pros and cons of participating. The following frequently asked questions (FAQ) modified from the NIH Clinical Trials website provide detailed information about clinical trials. In addition, it is helpful to talk to a physician or friends about joining a trial.

What is clinical research?

Clinical research is generally considered to be a health-related research study in human beings that follows a pre-defined plan. The Shiley-Marcos Alzheimer’s Disease Research Center conducts both observational and interventional types of research.

  • Observational studies are those in which individuals are observed and their outcomes are measured by the investigators. They are used to follow people who may already be receiving treatment for an illness while measuring their outcomes. These studies rely upon a more natural setting as participants select their treatment.
  • Interventional studies test promising treatments in a controlled environment. In these studies, the investigator assigns participants to particular treatment groups in order to measure and compare their outcomes at the end of the trial. These studies are also called "clinical trials" or "treatment trials." New treatments cannot be widely used until they have been shown to work safely in patients, and clinical trials are the standard used to judge these treatments as safe and effective.

What is a clinical trial?

A clinical trial is an interventional study and is generally considered to be a biomedical or health-related research study in human beings that follows a pre-defined protocol.

Rapid advances in our knowledge about AD have led to the development of many new drugs and treatment strategies. However, before these new strategies can be adopted, they must be shown to work in patients. This means that clinical trials—studies in people to rigorously test how well a treatment works—have become an increasingly important part of AD research. Advances in treatment are only possible through the participation of patients and study partners (a patient’s spouse, family member, caregiver or friend) in clinical trials.

Clinical trials are the primary way that researchers find out if a promising treatment is safe and effective for patients. Clinical trials also tell researchers which treatments are more effective than others. Trials take place at private research facilities, teaching hospitals, specialized AD research centers, and doctors' offices

Participating in a clinical trial is a big step for people with AD and their caregivers. That's why physicians and clinical trials staff spend lots of time talking with participants about what it's like to be in a trial and the pros and cons of participating. Here are some things that potential participants might want to know about clinical trials.

Why participate in a clinical trial?

Participants in clinical trials can play a more active role in their own health care, gain access to new research treatments before they are widely available, and help others by contributing to medical research.

Who can participate in a clinical trial?

All clinical trials have guidelines about who can participate. Using inclusion and exclusion criteria is an important principle of medical research that helps to produce reliable results. The factors that allow someone to participate in a clinical trial are called "inclusion criteria" and those that disallow someone from participating are called "exclusion criteria". These criteria are based on such factors as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. Before joining a clinical trial, a participant must qualify for the study. Some research studies seek participants with illnesses or conditions to be studied in the clinical trial, while others need healthy participants. It is important to note that inclusion and exclusion criteria are not used to reject people personally. Instead, the criteria are used to identify appropriate participants and keep them safe. The criteria help ensure that researchers will be able to answer the questions they plan to study.

What are some common inclusion and exclusion criteria for clinical trials?

Each study has specific inclusion and exclusion criteria and are based on such factors as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions. It is important to note that inclusion and exclusion criteria are not used to reject people personally, but rather to identify appropriate participants and keep them safe.

What happens during a clinical trial?

If participants agree to join the study and the screening process shows they're a good match, they have a "baseline" visit with the study staff.  This visit generally involves a full physical exam and extensive cognitive and physical tests. This gives the study team information against which to measure future mental and physical changes. Participants also receive the test drug or treatment. As the study progresses, participating patients and family members usually must follow strict medication or treatment instructions and keep detailed records of symptoms.

Every so often, participants visit the clinic or research center to have physical and cognitive exams, brain scans, give blood and urine samples, and talk with study staff. These visits allow the investigators to assess the effects of the test drug or treatment, see how the disease is progressing, and see how the participant and the caregiver are doing.

In most clinical trials, participants are randomly assigned to a study group. One group, the test group, receives the experimental drug. Other groups may receive a different drug or a placebo (an inactive substance that looks like the study drug). Having the different groups is important because only by comparing them can researchers be confident that changes in the test group are the result of the experimental treatment and not some other factor.
In many trials, no one—not even the study team—knows who is getting the experimental drug and who is getting the placebo or other drug. This is called "masking" meaning that the patient/family member and the staff are "blind" to the treatment being received.

What is informed consent?

Informed consent is the process of learning the key facts about a clinical trial before deciding whether or not to participate. If the participant's native language is not English, translation assistance can be provided. Then the research team provides an informed consent document that includes details about the study, such as its purpose, duration, required procedures, and key contacts. Risks and potential benefits are explained in the informed consent document. The participant then decides whether or not to sign the document. Informed consent is not a contract, and the participant may withdraw from the trial at any time.

What are the benefits and risks of participating in a clinical trial?


Clinical trials that are well-designed and well-executed are the best approach for eligible participants to:

  • Play an active role in their own health care.
  • Gain access to new research treatments before they are widely available.
  • Obtain expert medical care at leading health care facilities during the trial.
  • Help others by contributing to medical research.


There are risks to clinical trials.

  • There may be unpleasant, serious or even life-threatening side effects to experimental treatment.
  • The experimental treatment may not be effective for the participant.
  • The protocol may require more of their time and attention than would a non-protocol treatment, including trips to the study site, more treatments, hospital stays or complex dosage requirements.

What should people consider before participating in a trial?

People should know as much as possible about the clinical trial and feel comfortable asking the members of the health care team questions about it, the care expected while in a trial, and the cost of the trial. The following questions might be helpful for the participant to discuss with the health care team. Some of the answers to these questions are found in the informed consent document.

  • What is the purpose of the study?
  • Who is going to be in the study?
  • Why do researchers believe the experimental treatment being tested may be effective? Has it been tested before?
  • What kinds of tests and experimental treatments are involved?
  • How do the possible risks, side effects, and benefits in the study compare with my current treatment?
  • How might this trial affect my daily life?
  • How long will the trial last?
  • Will hospitalization be required?
  • Who will pay for the experimental treatment?
  • Will I be reimbursed for other expenses?
  • What type of long-term follow up care is part of this study?
  • How will I know that the experimental treatment is working? Will results of the trials be provided to me?
  • Who will be in charge of my care?

Who pays for research?

Clinical trials are paid for by the organizations that sponsor the study.  If it is sponsored by the government, it may be paid for through a grant awarded to the doctors and scientists who conduct the research.

Some research studies are sponsored and paid for by drug and medical device companies or by private foundations for specific diseases.

What is a protocol?

A protocol is a study plan on which all clinical trials are based. The plan is carefully designed to safeguard the health of the participants as well as answer specific research questions. A protocol describes what types of people may participate in the trial; the schedule of tests, procedures, medications, and dosages; and the length of the study. While in a clinical trial, participants following a protocol are seen regularly by the research staff to monitor their health and to determine the safety and effectiveness of their treatment.

What is a placebo?

A placebo is an inactive pill, liquid, or powder that has no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the experimental treatment's effectiveness. In some studies, the participants in the control group will receive a placebo instead of an active drug or experimental treatment.

What is a control or control group?

A control is the standard by which experimental observations are evaluated. In many clinical trials, one group of patients will be given an experimental drug or treatment, while the control group is given either a standard treatment for the illness or a placebo.

If you are interested, someone from our clinical trial staff will explain the details of the study, risks and benefits, and your rights as a participant, including your right to withdraw from the study at any point.  Once all your questions have been answered, they will ask you to sign an informed consent to participate.