In the largest genetic analysis of depression to date, researchers from Institute of Biological Psychiatry, in collaboration with researchers from all over the world, have discovered 44 genetic variants that affect the risk of developing depression.
This is the first time that researchers have managed to map such a significant number of risk genes for depression. The study makes it clear that the hereditary basis for depression is not single mutations with high disease risk, as it is the case for some forms of cancer, but instead in the interaction between many highly frequent low risk variations in our genes.
Prior to this study, 30 of the 44 genes were completely unknown in depression research. In addition, eight of the 44 genes were previously identified as risk genes for schizophrenia, which may explain that people suffering from schizophrenia, more frequently than others, develop depression.
Other genes identified by the new study are previously known from obesity and sleep disorders, which means that these complications often also affect people with depression.
“First and foremost, the study is a very clear confirmation that depression, like many other common diseases, is genetically conditioned. Secondly, the identified genes are almost exclusively tied to biological processes in the brain, indicating that depression is a brain disorder”, says Institute Director of IBP and co-author of the study Professor Thomas Werge.
The study is the largest of its kind and involves more than 200 researchers from the international collaboration, Psychiatric Genomics Consortium, 135,000 people with depression and 344,000 healthy control subjects.
The project is part of the Danish iPSYCH Inistiative supported by the Lundbeck Foundation.