Is depression ultimately just a story of genes? A large study published Monday, August 1, 2016 in the specialized journal Nature Genetics confirms the influence of genes on the risk of depression in people of European origin. For the purposes of this pan-genomic study, American researchers at Massachusetts General Hospital first analyzed the DNA of nearly 300,000 Europeans via saliva samples, obtained thanks to the biotechnology company 23andMe. They then compared them to the DNA of 75,600 people who had been diagnosed or treated for depression, as well as 230,000 people with no history of depression. Results ? 17 genetic variations potentially at risk, spread over fifteen regions of the genome. This first analysis reveals that the genes involved in depression are linked to the nervous system, or at least involved in brain development. A gene that was previously associated with epilepsy and intellectual disability is also involved.
The scientists then compared the DNA of nearly 20,000 people, half of whom were depressed, to more than 150,000 23andMe customers. Of these, nearly 46,000 people were depressed. The results of this second comparative study then highlight 15 genomic regions containing 15 genetic variations associated with depression. “Identifying the genes that influence risk for a disease is a first step towards understanding the biology of the disease itself,” explains Roy Perlis. Co-author of this work, he hopes that “these results will help show that depression is a disease of the brain, and that they will fight the stigma around this disease. In any case, this discovery constitutes a great advance for science and will help in the development of new treatments. According to the WHO, depression affects more than 350 million people worldwide, including 25% of the European population.
