Researchers have identified 44 genomic variants that have a significant association with depression, an advance that can be used for improving antidepressant medications.
The findings showed that the genetic basis of depression overlaps importantly with other psychiatric disorders like bipolar disorder and schizophrenia.
The meta-analysis of more than 135,000 people with major depression and more than 344,000 controls has identified 44 genomic variants with links to depression.
Of these 44 loci, 30 are newly discovered while 14 had been identified in previous studies.
In addition, the study identified 153 significant genes and found that major depression shared six loci that are also associated with schizophrenia, the researchers said in a paper published in the journal Nature Genetics.
"This study is a game-changer. Figuring out the genetic basis of major depression has been really hard. With more work, we should be able to develop tools important for treatment and even prevention of major depression," said Patrick F Sullivan, professor at the University of North Carolina in the US.
Intriguingly, the genetic basis of depressive disorder also overlaps with that for obesity and multiple measures of sleep quality, including daytime sleepiness, insomnia and tiredness.
While all people carry genetic variants for depression, but those with a higher burden are more susceptible, the study showed.
"We know that many life experiences also contribute to risk of depression, but identifying the genetic factors opens new doors for research into the biological drivers," added Naomi Wray, from the University of Queensland in Australia.