Viruses and schizophrenia: a focus on herpes simplex virus

Area of Science:

• Neuroscience
• Infectious Diseases
• Psychiatry

Background:

• Schizophrenia pathogenesis is multifactorial.
• Increased schizophrenia risk observed in individuals born during winter-spring months suggests infectious etiology.
• Herpes simplex virus (HSV) has a known neurotropic and neuroinvasive potential.

Purpose of the Study:

• To investigate the potential role of viral infections, specifically herpes simplex virus type 2 (HSV-2) and human endogenous retroviruses (HERVs), in the development of schizophrenia.

Main Methods:

• Nested case-control study analyzing stored maternal blood samples from 1959-1966.
• Assessed maternal antibody levels to HSV-1 and HSV-2 in relation to offspring schizophrenia diagnosis.
• Measured reverse transcriptase levels in cerebrospinal fluid (CSF) of recent-onset and long-term schizophrenia patients.

Main Results:

• A significant association was found between high maternal antibody levels to HSV-2 and the subsequent development of adult psychosis in offspring.
• No association was observed between maternal HSV-1 infection and psychosis.
• Elevated levels of reverse transcriptase, a marker for HERVs, were detected in the CSF of schizophrenia patients compared to controls.

Conclusions:

• Findings suggest a potential link between maternal HSV-2 infection and schizophrenia risk in offspring.
• Evidence supports a possible role for human endogenous retroviruses (HERVs) in schizophrenia.
• Further research is warranted to elucidate the relationship between viral infections and schizophrenia.