Treating depression has been a major challenge for medical professionals ever since it has been identified as a distinct mental disorder. Unlike with many other medical conditions, people with depression exhibit a wide variety of symptoms and respond to treatment in highly disparate ways.
Given that research has shown a clear genetic link in the past, many studies have focused on identifying specific culprits hidden deep in our own genetic make-up.
A new genome-wide association study, the largest of its kind to date, has looked at the genes of nearly 500,000 people (135,458 depressed individuals and 344,000 people without depression) and found 44 distinct genetic variants which contribute to a person’s risk of falling prey to depression – a mental disorder which affects around 14 percent of the global population, yet about half of those who get treatment are considered to be non-reponders.
“The new genetic variants discovered have the potential to revitalise depression treatment by opening up avenues for the discovery of new and improved therapies,” said Gerome Breen of King’s College London, one of the authors on the study.
Interestingly, the genetic variants were found to be linked with regions of the brain targeted by at least some of the antidepressant medications currently on the market, which indicates that even though their mechanisms remain opaque for the moment, there is clearly some benefit to taking them.
According to the researchers, nearly all humans carry at least some of these variants, which could potentially explain the highly unpredictable manner in which depression can strike people of all backgrounds and, seemingly, at any point in time.
As many as 30 of the genetic variants identified in the study weren’t known before, adding to our knowledge about one of the sneakiest and most debilitating mental disorders out there.
One limitation of the study was that it was done exclusively on people of European descent, highlighted by the research team by comparing their results to a study on depression and genetics in a Han Chinese population.
While the results are encouraging, “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,” said co-author on the study Cathryn Lewis from King’s College London.