A possible link between infections, COVID-19, and development of psychotic disorders like schizophrenia and bipolar disorder: new research in progress

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Severe virus infections have caused or at least been associated with development of psychiatric disorders like schizophrenia and bipolar disorder.  A new article in Medscape.com published May 8 adds COVID-19 to the list of possible cofactors.  Researchers Emily Severance, PhD, and Robert Yolken, MD at Johns Hopkins University in Baltimore are studying a possible association of the new virus with psychiatric disorders.

“Over the years there have been data showing an association between exposure to general respiratory viruses such as the flu and subsequent psychotic episodes. This association was especially evident in studies of the aftermath of the great influenza of 1918,” Severance, assistant professor of pediatrics, Johns Hopkins University, Baltimore, Maryland, told Medscape Medical News.

In a 2011 study, an association was found between common coronaviruses that cause colds and the development of psychiatric problems.  Two of these viruses, known as HKU1 and NL63 (that cause cold symptoms), were found to show particularly higher levels of antibodies in the blood of sufferers than in controls.  The researchers are building on this to start a new study comparing the four common cold viruses and the new coronaviruses– SARS (now known as SARS-COV-1), MERS, and SARS-COV-2 and their association with psychiatric disorders.

The best-known association between infection and mental disorder is the parasite Toxoplasma gondii (found in cat feces) and schizophrenia in the offspring of women who were pregnant when they came down with this infection.  A journal review study from 2018 tells us many details of the relationship of schizophrenia to this parasitic infection.  The relationship between other infections and psychiatric disorders is not as clear cut, but there are reasons to suspect that viral infections can cause mental problems.

The  novel coronavirus is particularly sneaky, and preliminary anecdotal reports suggest that psychosis and hallucinations can occur during the course of acute infection.  Night-time hallucinations have been reported by many who are ill with fever.  There are suggestions that this virus can directly infect nerve and brain structures, causing breakdown of normal signalling.  The loss of smell is one well-publicized example.

Influenza (not a coronavirus disease) can cause an increased risk of bipolar disorder by nearly four times in children of women who were acutely ill during pregnancy.  The risk for schizophrenia was even greater: a seven times increase occurred if women were infected in the first trimester.

The new study will use stored blood from patients with psychiatric disorders and collect new samples from those with and without COVID-19.  A barrier to this work is the higher priority of studies looking at treatments for, and susceptibility to, COVID-19.  Nonetheless, the researchers hope to complete sample collection within the year, possibly piggy-backed on other, more acute studies.

The aftermath of the pandemic may find us with post-traumatic stress symptoms among hospital workers as well as the general public who are exposed to others dying around them and the uncertainty surrounding this situation.  In addition, we will likely find an increase in serious psychiatric disorders after the pandemic has died out.

As a family physician and potential patient, I find that the multifarious manifestations of COVID-19 are especially disturbing.  Who knows when one of us will fall victim to this virus, or if not the virus, to the economic fallout from having to quarantine ourselves to avoid it?  Who knows what odd symptom may be a harbinger of acute infection?