Scientists discover hundreds of other genetic risk factors for depression | Depression

A global study identified 300 previously unknown genetic risk factors for depression because it included a much larger population sample.

According to the World Health Organization, 3.8% of the population suffers from depression at any given time, affecting approximately 280 million people.

Although a range of factors, including adverse life events, poor physical health and stress, can increase the risk of developing depression, there is also a genetic component to the condition.

An international team of researchers, led by the University of Edinburgh and King’s College London, studied the anonymized genetic data of more than 5 million people across 29 countries, including one in four of non-European ancestry.

Previous research into the genetics of depression has focused primarily on wealthier white populations, neglecting most of the world. But by including a more diverse sample, the authors were able to identify new risk factors.

The study, published in the journal Cell, revealed 700 variations in the genetic code of individuals linked to the development of depression, almost half of which had never been associated with the condition before.

These small changes in DNA were linked to neurons in several regions of the brain, including areas that control emotions.

In total, 100 previously unknown genetic differences were specifically identified because people of African, East Asian, Hispanic and South Asian descent were included in the study.

Although each genetic risk factor for depression is very small, the cumulative impact for individuals with multiple DNA variants may increase their risk, the study found.

The authors believe the findings will allow scientists to predict depression risk more accurately, regardless of ethnicity, and develop more diverse treatment options, helping to reduce health inequalities.

The study calculated that 308 genes were associated with a higher risk of depression. The researchers then looked at more than 1,600 drugs to see if they impacted these genes. In addition to antidepressants, the study identified that pregabalin, used to treat chronic pain, and Modafinil, used to treat narcolepsy, also had an effect on these genes and could therefore potentially be used to treat depression. Further studies and clinical trials would be needed to explore the potential of these drugs in patients with depression, the authors said.

Professor Andrew McIntosh, one of the lead authors of the study and from the University of Edinburgh’s Center for Clinical Brain Sciences, said: “There are huge gaps in our understanding of clinical depression that limit opportunities to improve outcomes for those affected.

“Larger, more globally representative studies are essential to provide the information needed to develop new and better therapies and to prevent disease in people at higher risk of developing the disease. »

Responding to the findings, Dr David Crepaz-Keay, head of research and applied learning at the Mental Health Foundation, said the study’s diverse gene pool was “a significant step forward”, but Genetic risk factors should not be used as a definitive criterion. treatment guide.

“While research like this can help develop measures for people at higher genetic risk, depression prevention needs to focus on broader societal issues that have a much greater impact on health mental, such as experiences of poverty or racism,” he added. .

Dr Jana de Villiers, spokesperson for the Royal College of Psychiatrists, said: “We welcome this research into genetic variants that may make people more susceptible to depression, and its diversity in terms of global representation makes it particularly noteworthy. . By improving our understanding of genetic risk factors and causes of mental illness, we may be able to develop better treatment methods.

“We will continue to support ongoing efforts to prevent mental illness and improve outcomes for people affected by depression. »