An analysis of data from over five million individuals across 29 countries has identified nearly 300 new genetic risk factors linked to depression. Researchers from the Psychiatric Genomics Consortium, led by teams at the University of Edinburgh and King's College London, revealed that about one-third of these genetic variations—small differences in the DNA sequence—were discovered by including participants of African, East Asian, Hispanic, and South Asian descent in the study.
One in four individuals included in the "world's largest and most diverse" genetic study, published in the journal 'Cell', were from non-European ancestries.
Each identified genetic variant contributes to the overall risk of developing depression, with multiple variants potentially compounding the risk. Previous studies on the genetics of psychiatric illnesses, including depression, have predominantly focused on individuals of European ancestry.
As a result, treatments derived from these studies may be less effective for people of other ethnicities, exacerbating existing health inequalities, researchers warned. "While depression is a growing major health issue, we lack the insights needed to better treat and prevent it," said Dr. Brittany Mitchell of the QIMR Berghofer Medical Research Institute, Australia.
"Larger, more inclusive studies like this will help us develop better treatments and interventions, ultimately improving lives and reducing the global impact of the condition. It will also reinforce the evidence that mental health conditions are as biologically based as other conditions like heart disease," she said.