In a medical first, scientists believe they have found several genes thought to be associated with severe depression. The study, carried out by Pfizer pharmaceuticals, scoured the genomes of 450,000 people in order to uncover 17 genes associated with significantly increased risk for developing depression. This finding not only gives researchers a better idea of the underlying cause of the condition, but may even help us better treat it.

In total, the study identified 17 genetic variations spread over 15 regions of the genome which are associated with the severe clinical depression in individuals of European descent.

To find these genes, the team examined data collected by the consumer genetic testing company 23andme. Of the 300,000 people studied, 75,607 self-reported a clinical diagnosis of depression or were receiving treatment for the condition.The DNA of people with the disease was then 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.

Lead study author Roy Perlis made it clear that these genes are not enough to allow for a depression diagnosis, but rather help researchers to better understand why some individuals get depression. Perlis also believes the findings act as further proof that depression is an actual brain disease completely different from general melancholy.

“Depression is about biology and I think that will be helpful for some people in reducing stigma and changing how we think about depression,” said Perlis, The Guardian reported.

The research was made possible largely through the use of genetic data supplied by the genetic testing company 23andme. Although the company mainly works by letting consumers know their genetic background for about $200, according to The Technology Review, about half of the customers agree to have their DNA used for research purposes. Having such a large amount of data to work with played an important role in the team’s ability to identify these terms.

Still, some doubt the reliability of using data from a consumer-based product such as the 23andMe self-reported testing. For example, Jonathan Flint, from the University of California in Los Angeles, told The Guardian that self-reported data is often flawed as individuals are not always guaranteed to be completely honest and accurate. In addition, many individuals with severe depression never receive a diagnosis. However, the data is more likely to break down the stigma of depression rather than be used for any specific drug developments. Understanding that depression is a real physical condition may help push some to receive help or treatment.

In addition, the success of the study helps to highlight the need for larger databases for genetic research. The U.S. government this year began implementing plans for a million-person precision medicine database to help understand and develop personalized health plans and treatments, according to The Technology Review.

Source:Hyde CL, Nagle HW, Tian C, et al. Identification of 15 genetic loci associated with risk of major depression in individuals of European descent. Nature . 2016