An international group of more than 200 researchers was able to map the genetic foundations of depression in greater detail than ever before. The study, published in Nature Genetics, has highlighted 44 gene variants that raise the risk of depression. Thirty of those had never been linked to the condition before.

Genetics is not the exclusive factor in the onset of depression. Life events and higher BMI also contribute to increasing the risk of developing the condition. This research builds on what we already know about the genetic variations targeted by current treatments and paves the way for potential new approaches in the future.

"With this study, depression genetics has advanced to the forefront of genetic discovery," co-author Dr Gerome Breen from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, said in a statement. "The new genetic variants discovered have the potential to revitalize depression treatment by opening up avenues for the discovery of new and improved therapies."

There is not a single gene for depression, and thousands of genes can play a modest role, but the combination of many of these might make people more susceptible to depression. The study included the data of 135,458 people with major depression and 344,901 controls. When ranked by their number of genetic risk factors for depression, the people in top 10 percent were 2.5 times more likely to experience the disorder than those in the bottom 10 percent.

“Depression is an incredibly common disorder that affects millions of people in the UK,” senior author Professor Cathryn Lewis, also from the IoPPN at King’s College London, added. “This study has shed a bright light on the genetic basis of depression, but it is only the first step. We need further research to uncover more of the genetic underpinnings, and to understand how genetics and environmental stressors work together to increase risk of depression.”

Major depression affects 14 percent of the world’s population and is by far the biggest contributor to long-term disability worldwide. Unfortunately, only about half of everyone diagnosed responds well to current treatments, which is why new studies such as these are extremely welcome.

The team wants to significantly expand the already wide-reaching study. Dr Breen and other members of the team are currently designing an online tool to recruit more people for further genetic studies. They hope to launch the project in the autumn.