In a significant development that could lead to more effective treatments for depression, researchers have identified 44 genetic variants that raise the risk of developing the disorder.

Of those 44 genetic variants, 30 are newly discovered, a study by the Psychiatric Genomics Consortium has found.

It’s the largest study to date looking at genetic risk factors for major depressive disorder, or MDD. The study, published Thursday in the journal Nature Genetics, found that the genetic basis for major depression is shared with other psychiatric disorders, including schizophrenia.

The study also found that all humans carry at least some of the 44 genetic risk factors linked to major depression.

Previous studies had also identified some genetic links to depression, but researchers say this is the most comprehensive analysis so far, and could help in the development of more targeted medications to treat depression.

The latest study is being described as “an unprecedented global effort,” involving more than 200 scientists and data from more than 135,000 people with major depression. The study also used data from 344,000 mentally healthy individuals as control subjects.

“With this study, depression genetics has advanced to the forefront of genetic discovery,” one of the researchers, Gerome Breen of King's College London in the U.K., said in a news release.

“The new genetic variants discovered have the potential to revitalize depression treatment by opening up avenues for the discovery of new and improved therapies."

The study notes that major depression affects approximately 14 per cent of the global population and is the biggest contributor to long term disability worldwide. However, only about half of patients respond well to existing treatments.

According to the Mood Disorders Society of Canada, about one in 10 Canadians will experience an episode of major depressive disorder during their lifetime.