For the first time, new genetic risk factors for depression have been discovered across all major global populations, enabling scientists to assess the risk of depression independent of ethnicity.
Experts have revealed that the largest and most diverse genetic investigation into major depression has uncovered nearly 300 previously unknown genetic connections to this condition.
Among the newly identified genetic variations — which refer to minor differences in the DNA that comprise genes — 100 were recognized due to the diverse backgrounds of participants, including individuals of African, East Asian, Hispanic, and South Asian heritage.
Earlier studies on the genetics of depression predominantly focused on white populations descended from European ancestry. This emphasis has resulted in treatments based on genetic findings potentially being less effective for other ethnic groups, thereby exacerbating health disparities.
While each genetic variant has a minimal influence on an individual’s likelihood of developing depression, having several such variants can accumulate and heighten overall risk.
The research team was able to provide a more precise prediction of a person’s depression risk by considering these newly identified genetic variants.
Led by the University of Edinburgh and King’s College London, the international team examined anonymized genetic data from over five million individuals across 29 countries. Notably, one in four participants hailed from non-European ancestries.
In total, researchers discovered 700 genetic variations associated with the onset of depression, nearly half of which had not been previously linked to the disorder, affecting 308 specific genes.
The discovered genetic variants were related to neurons — a type of brain cell — located in various brain regions, including those responsible for emotional regulation.
These findings shed light on how depression influences the brain and offer potential new avenues for treatment, according to experts.
The research team pointed out existing medications such as pregabalin, used for chronic pain, and modafinil, prescribed for narcolepsy, that might be repurposed for depression treatment based on their findings.
Nevertheless, the team stresses the need for additional studies and clinical trials to assess the effectiveness of these drugs in depression patients.
This study, supported by NIH, Wellcome, and the National Institute for Health and Care Research Maudsley Biomedical Research Centre, is published in the journal Cell.
The Psychiatric Genomics Consortium, which includes researchers from all continents, was involved in this study, incorporating data from South Africa, Brazil, Mexico, the USA, Australia, Taiwan, and China.
Professor Andrew McIntosh, a co-leader of the study from the University of Edinburgh’s Centre for Clinical Brain Sciences, commented: “There remains a significant lack of understanding regarding clinical depression, which hinders our ability to improve outcomes for those affected. Larger and more representative global studies are essential for gaining insights to develop new and more effective therapies, and to help prevent depression in at-risk populations.”
Professor Cathryn Lewis, co-leader from King’s College London’s Institute of Psychiatry, Psychology & Neuroscience, stated: “Depression is a common disorder and there is much more to learn about its biological foundations. Our research identifies numerous additional genetic variants involved in depression, demonstrating its highly polygenic nature and paving the way for translating these findings into improved care for individuals suffering from depression.”
For further information, please contact: Jess Conway, Press and PR Office, 07979 446 209, jess.conway@ed.ac.uk
