COVID is known to affect the brain, causing a range of symptoms and problems such as a loss of smell and taste, headaches, brain fog, confusion, and mental health issues, like depression.
In some cases, it can even trigger psychosis, a break with reality that is characterized by hallucinations, delusions, agitation, paranoia, and sometimes magical thinking. While that’s rare even in adults, researchers in the UK reported an even more unusual psychosis case in an unvaccinated 16-year-old boy who was admitted to the hospital for COVID-related breathlessness and chest pain.
About a week after his COVID infection subsided, he became agitated and believed he had special powers, including the ability to read minds. He was also hearing and seeing hallucinations, including Fortnite characters, according to Dr. Zainab Bashir, of the Queen Elizabeth Hospital Birmingham, and colleagues, who are the authors of the report in the journal Pediatrics.
Psychosis is unusual, but it’s not unheard of following viral infections in general, particularly those of the respiratory system. Other brain-related complications of COVID are more common, such as stroke, anxiety, insomnia, and confusion.
One study of more than 230,000 COVID patients who got sick in 2020 found that about 1 in 3 were diagnosed with a neurological or psychiatric condition in the six months following infection. However, only about 1.4% were diagnosed with a psychotic disorder.
“It’s a very rare occurrence. You're looking at a sliver of a slice of patients infected with COVID. But should everyone be worried that they're gonna develop COVID psychosis following an infection? No,” said Dr. Jonathan Komisar, an internist and psychiatrist at Duke University Hospital who regularly treats patients with COVID psychosis and other neuropsychiatric symptoms related to the disease.
Still, “it’s certainly not so rare that you shouldn't be keeping an open mind to the fact that stuff like this does happen,” he said.
Treatment can help, although the recovery time can vary
The most striking part of the UK teen’s case, according to the researchers, was the lack of warning signs to signal what was to come. (Not to mention he had no personal or family history of psychiatric illness or substance use.)
The boy was first admitted to the hospital for COVID for five days and then sent home. But three days later, his family brought him back after they noticed a sudden change in behavior.
The teen was unusually anxious, wasn’t speaking normally, would strip down to his underwear, and swear at his parents. At the hospital, the boy said he could see messages written on the ceiling, broke a glass in the door to attempt an escape, was typing in the air while mouthing gibberish, and said the “information system in his brain had been deleted.” Meanwhile, he refused to let doctors conduct tests, which he thought would poison him, and was expressing suicidal ideation.
The teen was admitted to an adolescent psychiatric ward and given low doses of antipsychotic medications, which gradually helped him improve and gain trust in hospital staff. Finally, after three months, he went home.
Six months later, he had fully recovered.
“Regardless of what leads to the psychosis, we're at least able to see that it does get better with time and with standard treatment, which I think is important,” Komisar said. “In a sense, it’s reassuring.”
Dr. Mujeeb Shad, an associate professor of psychiatry at the Oregon Health and Science University’s School of Medicine, published a report on three teens, including a 17-year-old patient he treated who developed COVID psychosis three weeks after testing positive. Their symptoms ranged from six days to six months, according to the report.
“This virus is one of the most complex viruses we've ever known, and nobody can predict which system it’s going to affect more than the other, whether it's the [central nervous system], the kidneys, the lungs, or even the skin,” Shad told BuzzFeed News.
It’s nearly impossible to tell if someone will develop psychosis or how severe their case may be, but Shad said it appears adults and those with compromised immune systems may be more vulnerable.
“This can be sort of a self-limiting process that can go on for months, but this happens in a small percentage of a small percentage of people,” Komisar said. “If you start to notice family members or children acting not like themselves or engaging in behaviors that aren't usual for them, that should raise a red flag and you should have them evaluated.”
Some possible explanations behind the cause of COVID-related psychosis
It’s not clear if the virus directly infects the brain or if it attacks certain immune system molecules that then harm brain cells, according to Shad.
The coronavirus is known to enter cells via ACE2 receptors, which normally bind to an enzyme abundant throughout the body, Shad said, which explains, at least in part, why the virus can affect nearly every cell.
Understanding the relationship between COVID and psychosis is also difficult because many factors can lead to mental health issues or neuropsychiatric symptoms in general, Komisar said, such as stress, the abuse of prescription or recreational drugs, brain injury, and of course psychotic or mood disorders themselves.
There doesn’t seem to be a clear link between the severity of an infection and the development or severity of psychosis symptoms, Shad said. The 17-year-old he treated, for example, experienced only mild respiratory symptoms, a low fever, and some fatigue.
One of the theories explaining COVID psychosis involves an invasion of the central nervous system, with the coronavirus causing direct damage to nerve tissue that leads to psychiatric symptoms. Or, Komisar said, the virus may trigger local inflammation in the brain that leads to psychosis.
Another involves a more exaggerated inflammatory response throughout the entire body. This reaction pumps an excessive amount of cytokines — proteins involved in communication between immune system cells that play a key role in inflammation — into the bloodstream, reducing or blocking blood flow to the brain. (This is called a cytokine storm.)
“You can think of it like a friendly fire,” Komisar said. “Your immune system is revved up and it starts confusing normal parts of your brain with infection and starts attacking it.”
The coronavirus itself can also be the “straw that broke the camel’s back,” Komisar said, meaning infection somehow triggers psychiatric illness in people who may have predisposing risk factors. However, because of a lack of data, doctors don’t have a clear understanding of what those risk factors are.
Corticosteroids, used to treat a number of conditions such as cancer, chronic pain, lupus, asthma, and that cytokine storm we mentioned, are known to cause psychosis and other mood-altering effects in some people and/or worsen psychosis when given during an episode.
None of the COVID psychosis patients featured in published case reports were taking steroids before their symptoms began, but both Komisar and Shad said it’s important to remember these medications must be used with caution.
Important to note, too, is that people can develop COVID psychosis because of the social and medical stress associated with the disease, not because of the disease itself. Shad describes two such cases of COVID-related psychosis in adolescents in his review.
“We are learning more and more that the closure of schools and not being able to interact with peers has actually caused significant damage in younger populations, reflected by the increased suicidality and increased number of suicides in young patients,” he said.
Psychosis after viral infections is well documented
Psychosis or other neurologic symptoms following a viral infection isn’t common, but it happens, experts say.
Some of the earlier evidence dates back to the 1918 flu pandemic. Some studies even reveal an association between prenatal exposure to influenza and a higher risk of a schizophrenia diagnosis.
Narcolepsy, seizures, Guillain-Barré syndrome, and encephalitis (inflammation of the brain) have also been reported after other outbreaks and pandemics, including the SARS epidemic in 2003, the H1N1 pandemic in 2009, and the MERS outbreak in 2012.
A 2020 review published in the journal Schizophrenia Research that included data from several epidemics and pandemics such as SARS, Ebola, H1N1, and COVID found that psychosis occurred in 0.9% to 4% of infections.
“The COVID pandemic is going to provide really important scientific opportunities to learn more about the relationships between viral infections and mental health disorders broadly and psychosis in particular,” said Dr. Sarah Morris, the chief of the Psychotic Disorders Research Program with the National Institute of Mental Health Division of Translational Research. “But it's important to avoid overstating the risk. We’re talking about very small percentages in the general population.”