In Brief
Researchers analyzed more than 400,000 customer DNA records from gene company 23andMe. In the research they found 15 human genomes linked to serious depression.

Biggest Study Of Its Kind

A new study found that 15 regions of the human genome are being linked to a higher risk of having serious depression.

Pharmaceutical giant Pfizer, in collaboration with California-based gene company 23andMe, funded the study to further locate genetic risks for depression. 23andMe is a company selling genetic testing kits typically used for personal entertainment, such as learning one’s ethnic background.

Previous efforts have been too small to find anything, so Pfizer and 23andMe conducted tests on more than 400,000 people. More than half of 23andMe customers or those who have used their gene-test kits agreed to allow their DNA to be used in further research and answer survey questions about their health.

Image source: Harvard University
Image Credit: Harvard University

Gene Hunting

23andMe customer surveys identified more than 141,000 people who said they’d been diagnosed with depression. DNA data on another 337,000 customers who reported no depression were used as controls.

Researcher conducted a “genome-wide association study,” where the DNA of people with a depression is compared that of healthy controls, using a computerized search. Any genetic differences appearing more often in sick people can hint at what genes are involved.

“The big story is that 23andMe got us over the inflection point for depression,” says Douglas Levinson, a psychiatrist and gene researcher at Stanford University involved with the Psychiatric Genomics Consortium, another gene-hunting group. “That is exciting. It makes us optimistic that we are finally there.”

Researchers are pushing larger studies on depression, and consequently, the U.S. government began implementing plans for a million-person precision medicine database. Experts say the genetic risk for depression is caused by not just 15, but hundreds of genes, and they want to identify what those genes are.