What new personal DNA testing can tell us about depression

The Takeaway
Blood samples are processed at Biobank

In the ongoing struggle to understand the biology of depression, there's been a promising new breakthrough, thanks in part to a popular at-home DNA test. Gene-testing company 23andMe and Pfizer Pharmaceuticals collaborated to explore the DNA of roughly half a million people, nearly 10 times more people than similar studies.

23andMe collected and sequenced DNA samples of more than 141,000 people diagnosed with depression and compared it with other crowd-sourced DNA samples of those unafflicted. This unprecedented wealth of genome data for depression research has led researchers to 15 specific regions in the human genome that could signal a risk of clinical depression.

Dr. Ashley Winslow headed the research team. She's the neurogenetics director at the University of Pennsylvania's Orphan Disease Center, and she worked as a neuroscientist at Pfizer during the study. She notes that there’s still plenty of work to do, trying to pick apart the 15 landmarks.

“Now we need to identify within those regions the specific mutations or genomic changes that cause disease,” says Winslow, “then identify the genes that are involved in that process, and then understand the biology — what goes awry, how do these genes alter the gene function?”

Because depression is considered a complex disorder, the “add-on effect” must be considered in research. “It’s hard to use genetics in a vacuum,” says Winslow, but examining how the genomes interact with each other and potentially environmental risk factors, like stress and light, results in a more holistic picture. The researchers haven’t yet looked at potential evolutionary factors, but different types and subtypes of depression may point to different underlying biological and environmental causes, which would lend itself to various forms of treatment.

Winslow says that because depression is so widespread, it’s “very common compared to other neurological diseases,” and seems to affect all kinds of people. The study pulled data from all ages, varying from early 20s to folks over 60 all afflicted by depression.

“Because depression is heritable, we would expect to see in studies there is a genetic component,” says Winslow, but this is the first study that has been able to identify points in the genome that are associated with risk of depression.

This study is just the beginning of how science can conduct research with the aid of crowd-sourcing technologies. Genes for Good is conducting similar research, and on a grander scale, Apple is working with researchers on a system for collecting health data from iPhone users. 23andMe continues to research and study diseases, often in partnership with academic institutions and pharmaceutical companies.

The more accessible and far-reaching medical information has gotten in this new age of technology, the deeper researchers can go in trying to address afflictions.

This story was first published as an interview on PRI's The Takeaway, a public radio program that invites you to be part of the American conversation.

Sign up for our daily newsletter

Sign up for The Top of the World, delivered to your inbox every weekday morning.