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No Risk in Disclosing Genetic Risks
15 July 2009 (All day)
Sitting in your doctor's office, you get the bad news: Thanks to a faulty gene, you're 15 times more likely than the average person to develop Alzheimer's disease (AD). But despite the diagnosis, you're unlikely to become more anxious or depressed within the next year, according to a new study.
In this age of relatively easy genome sequencing, anyone can send their saliva to a company and learn their risk of developing a variety of genetic diseases. But is this a good thing? Researchers and bioethicists worry that bad news could traumatize patients and cause depression or other psychological harm (Science, 22 February 2008, p. 1022). Few studies, however, have investigated the psychological effects of finding out this information.
Begun in 2000, the Risk Evaluation and Education for Alzheimer's disease (REVEAL) study set out to answer the question for AD. The study's authors chose AD because there is currently no treatment, so news of being at risk for the disease could be devastating. The REVEAL team recruited subjects who had a parent or sibling suffering from AD and who had signed up to learn about their apolipoprotein E, or APOE, genotype. People who have one copy of the APOE gene variant e4 have a three times greater risk of developing AD. Patients with two copies have a 15-fold risk increase.
To get a read on the volunteers' baseline mental status, REVEAL team members used standard psychological questionnaires to screen them for depression and anxiety. Genetic counselors then gave a presentation about the APOE gene and AD risk statistics. Finally, the scientists drew blood samples and split the volunteers into three groups for further meetings with counselors. Members of one group learned nothing about their APOE status, one group was given the good news that its members were not at increased risk for AD, and the final group was given the bad news that its members were at increased risk. Three times in the next year, the researchers measured the subjects' depression, anxiety, and distress levels.
Not surprisingly, volunteers who received the good news tended to be more relieved throughout the year than were subjects getting bad news, the team reports tomorrow in The New England Journal of Medicine. But subjects who learned that they had an increased Alzheimer's risk were no more depressed, anxious, or distressed than subjects who were unaware of their APOE genotype, the researchers found. And 1 year after receiving the bad news, the e4-positive group was no more depressed than when they started the study.
That may explain why 98% of the e4-positive subjects said they would still get tested if they had the choice again, says Robert Green, the Boston University neurologist who led the study: "If this information was a drug, ... it looks pretty safe in this small group of screened individuals."
Experts say the study provides much-needed data about the psychological impact of genetic testing. But they have reservations about generalizing the results. Henry Greely, a bioethicist at Stanford Law School in Palo Alto, California, worries that patients will not receive the same level of counseling as the study's participants did from a busy doctor or through a genetic-testing company's online report. And Kenneth Offit, a cancer geneticist at the Memorial Sloan-Kettering Cancer Center in New York City, says the AD results may not be applicable to other diseases. AD is usually a late-onset illness, he notes, whereas breast cancer can affect much younger patients--and thus news of being at high-risk for breast cancer may be more traumatic. "There is not a one-size-fits-all approach to genetic testing," he says.