The hepatitis C virus (HCV) can play a role in mental health disorders such as schizophrenia, bipolar disorder and major depression, according to a new study.
Experts have long noted links between these psychiatric disorders and some viral infections, but direct evidence of viruses There is no inside of the human brain.
However, in the brain’s protective mucosa, the new study finds traces of 13 different viral species. HCV showed a significant connection with both schizophrenia and bipolar disorder compared to healthy controls.
Related: mysterious viral DNA in the human genome associated with psychiatric disorders
A study, led by researchers at John Hopkins University, analyzes brain samples after death by patients diagnosed with schizophrenia, bipolar disorder and major depression, as well as unaffected subjects to serve as controls.
They focused on the choroid plexus, a network of capillaries and connective tissue that Controls the production of cerebrospinal fluid. These things surround the brain and spinal cord to a pillow against impact, helps to eliminate metabolic waste from the brain and regulate the exchange of incoming and outgoing molecules.
The choroid plexus is known to be a goal virusesAnd since previous studies have found so few viral traces in the brain itself, the authors of the new study consider this structure a good place to look a good look.
They acquired samples from the collection of the Institute for Medical Research of Stanley, Brain Tissue storage to study mental health people.
To hunt for hidden virusesResearchers have conducted a sequence with a comprehensive viral research panel that can help identify more than 3000 different viruses in human samples.
This reveals an array of viral sequences in the choroid plexus, especially in samples of patients who had schizophrenia or bipolar disorder.
While these samples are more likely to contain viruses In general, HCV is the only viral species with a statistically significant relationship, the study found.
Thus the researchers chose him “to characterize the relationship between psychiatric disorders and viruses“They write.
In the second phase of the study, the authors decreased from separate brain samples to analyze Trinetx, a huge database of health records of 285 million patients.
Using these records, they found HCV at 3.5 percent of patients with schizophrenia and 3.9 percent of those with bipolar disorder.
This is almost twice the greater spread of HCV in patients with high depression (1.8 percent), the researchers noted seven times more than the distribution in the control population (0.5 percent).
The new survey found evidence of viruses Only in the cerebral mucosa, although it also inspects hippocampus samples – a brain region involved in learning, memory and emotion, among other roles.
The hippocampus was reliably clean, even if the mucosa was not. The protective layer seems to effectively do its work to protect pathogens outside the brain.
Still, patients with HCV in the mucous membrane show a changed gene expression in the hippocampus, suggesting how a virus can have influence from the boundaries of the brain.
More research is still needed to clarify associations between viruses and psychiatric disorders and examine the possible mechanisms that could allow pathogens to pull strings from the periphery.
Even if HCV can contribute to these conditions, it would not mean that this is the only factor. New discoveries do not suggest that everyone with schizophrenia or bipolar disorder has HCV, the authors say.
However, they offer hope for new tactics against devastating psychiatric disorders, says Sarven Sakunyan, a neuroscience in John Hopkins.
“Our discoveries show that it is possible for some people to have psychiatric symptoms because they have an infection and since hepatitis C infection is treatable, it may be possible for this subset of the patient to be treated with antiviral drugs and not have to deal with psychiatric symptoms,” says Sakundzhian.
The study has been published in Translational psychiatryS