New medications, gene transfer interventions involving the injection of genes into the brain, and 'vaccines' designed to trigger the immune system to fight Alzheimer's from within are promising, but still experimental, ideas that carry risks along with their potential benefits.

Researchers at the University of Michigan and the University of Rochester examined this issue in depth for the first time and expressed some surprise at their findings.

In all, 90 percent of adults in the study said that it would be all right to allow a family member to enroll a person with Alzheimer's disease in studies that involved mild to medium risks, including studies of new drugs.

A smaller percentage, but still a majority, approved of such surrogate decision-making for studies involving gene transfers, Alzheimer’s protein "vaccines," spinal taps and brain tissue sampling.

When the 229 study participants were asked which kinds of studies they themselves would allow if they were acting as the surrogate for a loved one, the percentages dropped, but were still high, especially when they perceived the risk to be low.

These results may help guide policymakers as they struggle to create a national standard for how and when surrogates can make decisions about enrolling adults who have lost their ability to give informed consent due to dementia in research studies. Currently, federal law allows surrogates but lets states set the conditions for such decisions. There is wide variation among states.

Heavy New Weapons

Consistent standards are needed, says lead author Scott Kim, MD, PhD, a U-M assistant professor of psychiatry who specializes in the ethics of research involving people who cannot give their own permission because of dementia or mental illness.

"Right now, Alzheimer's studies being done in one state could be illegal in others, and most states, such as Michigan, have no clear law on this issue," notes Dr. Kim.

"Though individual research institutions, such as universities, do their best to protect research participants, they deserve better policy guidance than what they have now," he says. "Our study aims to provide data about the attitudes of key stakeholders that policy makers can use." Kim recently received federal funding for a new study of consent abilities in Alzheimer's patients.

In recent years, researchers have brought out some heavy new weapons to test in the fight against Alzheimer's disease, including new medications, gene transfer interventions involving the injection of genes into the brain, and "vaccines" designed to trigger the immune system to fight the disease from within. All of these promising, but still experimental, ideas carry risks along with their potential benefits.

Indeed, a recent national vaccine study was stopped early by its safety board, headed by a U-M researcher, because of brain inflammation in some participants. Two patients in a recent California gene-therapy trial experienced bleeding in the brain.

In addition, researchers who seek to understand Alzheimer's better are using brain scanning and samples of blood and spinal fluid taken from patients. Such studies don't benefit study participants and can carry burdens, but they may lead to discoveries that could benefit future patients.

Majority Find Risks Acceptable

Dr. Kim and his colleagues set out to measure the attitudes of adults toward many kinds of research. All of the study participants had a heightened risk of developing Alzheimer's disease: They were over the age of 70 and had at least one close blood relative diagnosed with dementia. All were taking part in a study on the ability of anti-inflammatory drugs to prevent dementia.

The participants were mailed a packet containing information about the issue of research involving people unable to give consent due to dementia, and 10 scenarios describing different studies. They also were asked about their own health, demographics and attitudes toward biomedical research.

For each research scenario, participants were asked to assess their perception of how risky each study would be. They then indicated how willing they would be to take part in such a study themselves, how willing they would be to allow a loved one for whom they had surrogate decision-making power to take part, and how acceptable they thought it would be for society to allow the study to take place.

In all, the vast majority of participants perceived that there was little risk from studies based on observation of patients, interviews with patients, and the drawing of blood. Over 90 percent said such studies should definitely or probably be allowed by society. A similar proportion found clinical trials of new drugs acceptable.

A slightly larger percentage of respondents would be willing to participate in such studies themselves while lower percentages, but still large majorities, said they would allow a loved one to take part.

Even studies that the participants perceived as somewhat riskier, such as lumbar punctures (spinal taps) or a drug challenge to probe the brain's function, were still seen as probably or definitely acceptable by sizable majorities.

Views of Key Stakeholders

The participants perceived the highest risk from studies involving gene transfer, Alzheimer's vaccine and brain biopsy or tissue sampling. But despite the risk, more than 50 percent said they thought it was acceptable for society to allow such studies, and a majority said they would probably or definitely take part.

When asked if they would consent to allow a loved one to take part, the percentage saying probably or definitely yes fell just below 50 percent for gene transfer and biopsy.

The results need to be interpreted with caution, Dr. Kim notes, because the study participants already were participating in an Alzheimer's-prevention study. It is likely they were more pro-research than the average American. On the other hand, their characteristics were similar to participants in current research studies on Alzheimer's disease.

"The ethics of research involving adults who cannot consent for themselves has been debated for nearly three decades in this country without a clear resolution," says Dr. Kim.

"Virtually none of that debate has been informed by views of key stakeholders, such as those at risk for dementia," he points out. "There are no a priori right answers, but a policy should take into account the views of those who will be most affected by it."

In addition to Dr. Kim, who is a member of the U-M Bioethics Program and the Center for Behavioral and Decision Sciences in Medicine, the researchers include Hyungjin Myra Kim, DSc, of the U-M School of Public Health and Colleen McCallum, MSW, and Pierre Tariot, MD, of the University of Rochester. The study was funded by the National Institutes of Health.