Ancient Viral DNA Sequences Linked to Mental Illness Risk, Study Finds

A groundbreaking study published in Nature Communications has uncovered a significant link between ancient viral DNA sequences and the risk of psychiatric disorders such as schizophrenia, bipolar disorder, and depression. Contrary to previous beliefs that these sequences, known as Human Endogenous Retroviruses (HERVs), were non-functional “junk DNA,” researchers have found that they are actively expressed in the human brain and may play a pivotal role in mental health.

Key Findings:

Ancient viral DNA sequences, previously considered “junk DNA,” are expressed in the human brain.

Specific HERVs are associated with an increased risk for psychiatric disorders.

Understanding the function of these ancient viruses could revolutionize mental health research and treatment.

Funded in part by the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre and the US National Institutes of Health (NIH), the study examined data from large-scale genetic studies involving tens of thousands of individuals with and without psychiatric disorders. Additionally, autopsy brain samples from 800 individuals were analyzed to explore the impact of DNA variations linked to psychiatric disorders on the expression of HERVs.

Dr. Timothy Powell, co-senior author of the study and Senior Lecturer at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London, emphasized the importance of the study’s findings: “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.”

The study identified five robust HERV expression signatures associated with psychiatric disorders, including variants linked to schizophrenia, bipolar disorder, and depression. Dr. Rodrigo Duarte, the study’s first author and Research Fellow at the IoPPN, King’s College London, noted, “Whilst it is not clear yet how these HERVs affect brain cells to confer this increase in risk, our findings suggest that their expression regulation is important for brain function.”

Dr. Douglas Nixon, co-senior author of the study and researcher at the Feinstein Institutes for Medical Research at Northwell Health, highlighted the need for further research to elucidate the exact function of HERVs. He stated, “We think that a better understanding of these ancient viruses, and the known genes implicated in psychiatric disorders, have the potential to revolutionize mental health research and lead to novel ways to treat or diagnose these conditions.”

This groundbreaking study opens new avenues for understanding the genetic underpinnings of psychiatric disorders and may pave the way for innovative approaches to diagnosis and treatment.