Researchers at Washington University School of Medicine in St. Louis and King’s College London have independently identified DNA on chromosome 3 that appears to be related to depression.

Major depression affects approximately 20 percent of people at some point during their lives, and family studies have long suggested that depression risk is influenced by genetics. The new studies identify a DNA region containing up to 90 genes. Both are published May 16 in the American Journal of Psychiatry.

“What’s remarkable is that both groups found exactly the same region in two separate studies,” says senior investigator Pamela A. F. Madden, PhD, professor of psychiatry at Washington University. “We were working independently and not collaborating on any level, but as we looked for ways to replicate our findings, the group in London contacted us to say, ‘We have the same linkage peak, and it’s significant.’”

Madden and the other researchers believe it is likely that many genes are involved in depression. While the new findings won’t benefit patients immediately, the discovery is an important step toward understanding what may be happening at the genetic and molecular levels, she says.