A scientific expedition into the DNA of more than 450,000 customers of gene-testing company 23andMe has uncovered the first major trove of genetic clues to the cause of depression.
The study, the largest of its kind, detected 15 regions of human genome linked to a higher risk of struggling with serious depression. The study was carried out by drug giant Pfizer as part of an alliance with 23andMe, the California company whose gene reports have been purchased by more than 1.2 million people.
So far the vast majority of efforts to locate genetic risks for depression have failed, probably because the efforts have been too small to find anything.
“Everyone is recognizing that this is a numbers problem,” says Ashley Winslow, formerly a neuroscientist at Pfizer and now the director of neurogenetics at the Orphan Disease Center at the University of Pennsylvania. Winslow led the research effort. “It’s hard if not impossible to get to the numbers that we saw in the 23andMe study.”
The results emerged from what is termed a “genome-wide association study.” In this approach, the DNA of many people with a disease is compared to that of healthy controls, using a computerized search. Any genetic differences appearing more often in sick people can hint at what genes are involved.