Thursday, January 17, 2008

Gene Testing for Mental Illness

The latest issue of Science has two interesting "News Focus" stories on gene testing for mental illness by Jennifer Couzin. The first is entitled "Gene Tests for Psychiatric Risk Polarize Researchers". Here is a sample:

Starting a biotechnology company was not part of John Kelsoe's life plan. A respected psychiatric geneticist here at the University of California, San Diego (UCSD), he has spent 20 years patiently searching for the genes behind bipolar disorder, tracing patterns of inheritance in families from Amish Pennsylvania to Iceland. Kelsoe has now laid this solid reputation on the line: He has founded a company that last year quietly began selling the first gene test to help diagnose people with bipolar disorder, which affects about 1% of the population.

Kelsoe knows well that he is opening himself up to harsh criticism. And it has begun: Francis Collins, director of the National Human Genome Research Institute (NHGRI) in Bethesda, Maryland, was taken aback to learn that a gene test for bipolar disorder was on the market. Being diagnosed with a mental disorder carries "great significance," says Collins, who, like many in the field, thinks a test based on current knowledge is likely to be misleading. In Collins's list of accepted genes for common diseases, "there are no entries" yet for bipolar disorder, he says.

....Because of this uncertainty, not to mention concern about how test results will be interpreted, researchers and ethicists are asking difficult questions. Why test for genes whose science is shaky or that boost risk only slightly? Who will buy these tests? And how will consumers understand and cope with the genetic information they're given?

The second story is "Hoping for a Glimpse of What's Ahead". Here is a sample:

It's one of the first questions people ask about testing for a gene associated with mental illness: Who would want to know the result? One ready volunteer for testing is Holly Finn, 13, who lives in Grand Rapids, Michigan, with her parents and her 16-year-old sister, Katherine. Holly's mother, Kristin Finn, was diagnosed with bipolar disorder 3 months before her 17th birthday. She says that Katherine began showing signs of depression and difficulty concentrating in the fourth grade. Initially pegged as having attention deficit hyperactivity disorder (ADHD), Katherine received a bipolar diagnosis in July of 2004, when she was 12. It's been a rocky road: Katherine has switched schools three times and suffered taunting from her peers, says her mother, an active member of the Depression and Bipolar Support Alliance in Chicago, Illinois.

Now the younger Finn daughter, Holly, is being treated for ADHD and anxiety. Her symptoms are different from her sister's, and she is not thought to have bipolar disorder. But, Holly says, having witnessed her sister struggle for years, she would welcome testing for a bipolar gene. "I think I might have a chance of having bipolar disorder," says Holly, who writes songs she plays on her guitar to cope with her sister's ups and downs. A test could help her "get to the bottom of" her symptoms, Holly says, or at least prod her and her psychiatrist to keep an eye out for bipolar disorder down the road. "It certainly wouldn't hurt."

But hurt is exactly what many are afraid of. "Some people would say individuals have a right to this information and shouldn't be barred by the medical community from receiving it," says psychiatrist Jinger Hoop of the Medical College of Wisconsin in Milwaukee, who is studying how people with schizophrenia or at risk for it respond to genetic data. Her work has confirmed what others have seen: Consumers often react favorably to hypothetical genetic knowledge. "But we don't know a lot about what the actual risks and benefits are" of receiving genetic results, Hoop notes. "We really need empirical data to let us know how people would interpret very subtle changes in risk."