The relationship between ancient viral DNA and mental illness

New research led by King's College London (KCL) has discovered thousands of DNA sequences originating from ancient viral infections expressed in the brain.

Some DNA sequences contribute to mental illnesses such as schizophrenia, bipolar disorder and depression.

About 8% of our genome consists of sequences called Human Endogenous Retroviruses (HERVs) , which are the products of ancient viral infections that our ancestors had hundreds of thousands of years ago. Until recently, it was thought that these "fossil viruses" were simply junk DNA , with no important functions in the body. However, advances in gene research have helped better understand their expression and function.

Ancient viral DNA in the human genome may affect the brain and the risk of certain mental disorders. (Photo: AI).

The authors analyzed data from large-scale genetic studies of tens of thousands of people with and without mental health problems; as well as the results of brain analysis on 800 donated bodies. A total of five markers of strong HERV expression associated with psychiatric disorders were identified, each increasing the risk of 1 or 2 of the above psychiatric disorders.

According to the authors, a better understanding of these ancient viruses and how the DNA associated with them impacts mental health has the potential to revolutionize research in this field, leading to new methods. new to treat or diagnose certain types of complex mental disorders.