Home / Issues and Investigations / Fossil Viruses Hidden in Our DNA Thousands of Years Ago Could Be the Cause of Depression

Fossil Viruses Hidden in Our DNA Thousands of Years Ago Could Be the Cause of Depression

Ancient DNA present in humans may be linked to major psychiatric disorders like depression, researchers have said.

DNA sequences originating from ancient infections are found in the brain, with some contributing to susceptibility for conditions like schizophrenia, bipolar disorder, and depression, a study found.

 About 8% of the genome (the complete set of DNA) is made up of sequences called Human Endogenous Retroviruses (HERVs) – products of ancient viral infections that occurred hundreds of thousands of years ago.
It had been thought that these fossil viruses had no important function and were simply junk DNA.

However, scientists have discovered where in our DNA these fossil viruses are located, helping them to understand what functions they may have.

The study is the first to show that a set of specific HERVs expressed in the human brain contribute to psychiatric disorder susceptibility.

Dr Timothy Powell, co-senior author on the study and Senior Lecturer at the Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London, said: “This study uses a novel and robust approach to assess how genetic susceptibility for psychiatric disorders imparts its effects on the expression of ancient viral sequences present in the modern human genome.

“Our results suggest that these viral sequences probably play a more important role in the human brain than originally thought, with specific HERV expression profiles being associated with an increased susceptibility for some psychiatric disorders”.

 Researchers looked at data from large studies involving tens of thousands of people, both with and without mental health conditions, as well as information from autopsy brain samples from 800 people.

They found that some genes preferentially affected the expression of HERVs.

The researchers reported five robust HERV expression signatures associated with psychiatric disorders, including two that are associated with risk for schizophrenia, one associated with risk for both bipolar disorder and schizophrenia, and one associated with risk for depression….


Dr Douglas Nixon, co-senior author on the study and researcher at the Feinstein Institutes for Medical Research at Northwell Health, USA, said: “Further research is needed to understand the exact function of most HERVs, including those identified in our study.

“We think that a better understanding of these ancient viruses, and the known genes implicated in psychiatric disorders, have the potential to revolutionise mental health research and lead to novel ways to treat or diagnose these conditions”.

The Independent


Leave a Reply

Your email address will not be published. Required fields are marked *