Do you have the gene for depression?

By Walter Armstrong

Genetic testing to prevent and treat disease is the next big thing in medicine, and researchers are rushing to be the first to identify—and cash in on—genes that may cause common medical conditions and drugs with hefty price tags. A husband-and-wife shrink team may have just hit the lottery by patenting their discovery of an entire gene family that looks like it's linked to depression, the world's leading cause of disability. The problem often goes undiagnosed, especially in men ages 20 to 50; alcohol and drug use often mask the symptoms.

Ma-Li Wong, MD, and Julio Licinio, MD, of the University of Miami School of Medicine, ran tests on the genes of some 600 adults. They zeroed in on a cluster of 21 genes that produce a specific protein believed to be key in brain chemistry and possibly mood. The folks who had been diagnosed with clinical depression, it turned out, were twice as likely to have a mutation, or damage, in one particular gene. "In our biased opinion," Dr. Wong told the National Academy of Sciences on Monday, "this looks like a strong lead for future treatment."

The shrinks hedged their bets by also dabbling in a little applied gene testing, a.k.a. pharmacogenetics. This is the trendy and pricey practice of matching medications with a person's own genetic blueprint. When Wong and Licinio treated their depressed patients with two top-selling antidepressants, they discovered—ka-ching!—that the drugs were four to nine times more likely to work in those who have specific mutations in that family of genes.

These mutations may serve as markers for medication. "If a marker would tell us who's likely to respond, that would be a big help," Licinio said. "Now, it's like a big guessing game. You don't know which drugs are going to work for which person."

Gene screens and drug tailoring could save us all major money and misery. But don't wait around for that before dealing with depression. Although gene screens can already be ordered on the Internet for over 1,000 medical problems, the kits run anywhere from a few hundred to a few thousand bucks. Any multiple-mutation test likely to be developed from Wong and Licinio's patents will probably take years to develop and cost even more—at least until the insurance industry catches on to the price-saving benefits of leaner, meaner gene medicine.