"This is so scary": COVID-19 link to neurological and mental disorders alarms experts

COVID-19's impact on mental health
COVID-19's impact on mental health 05:34

One in three COVID-19 survivors suffer from a neurological or mental disorder within six months of infection, according to a University of Oxford-led study looking mostly at American patients. 

Among patients treated in the ICU, 7% suffered a stroke and nearly 2% were diagnosed with dementia. Researchers also found 17% of patients developed anxiety, and 14% experienced mood disorders.

"People that are most at risk are the ones who were the sickest, the hospitalized patients who were in the ICU. Those are the ones who are more at risk for the more serious conditions," psychiatrist Dr. Sue Varma said on "CBS This Morning" Thursday. "The scariest part are people who didn't have either COVID symptoms or very mild COVID symptoms that resolved, or prior psychiatric known illnesses, they too are at risk for the anxiety and the depression."

The study found people reporting these neurological and mental health impairments have, in many cases, never experienced them before. 

"That is so scary, especially when you hear voices or the voices are telling you to harm yourself or harm other people or that other people are out to get you," Varma said. 

Varma, who is not affiliated with the study, noted it could be sometimes difficult to separate the virus' impacts from the impacts of the pandemic's economic and other effects. 

And while similar symptoms can appear after other viral infections, the study found that people who were sick with COVID-19 were twice as likely to exhibit them compared to influenza sufferers. 

"Never underestimate or minimize your mental health concerns, because they very much may be linked to the inflammation that COVID caused in the body," Varma said.

The sudden shift in mental health has caught many COVID-19 sufferers off-guard, including 50-year-old adventure photographer Ivan Agerton from Seattle. He compared the change to a light switch after recovering from his infection.

"I felt this intense paranoia hit me," Agerton told CBS News' Ian Lee. "I couldn't escape it — every single person I saw would trigger this intense fear."

When the former Marine first came down with COVID, he feared for the health of his wife and three small children. It was after he thought he had recovered that he began feeling what he recognized as mental illness. 

"I was hearing voices outside my window. I thought I heard people in the bushes," he recalled. "It was absolutely the most terrifying thing I've ever experienced in my life."

There was a turning point, however — after receiving his vaccination two weeks prior, Agerton said he "started feeling really good."

And while his new disorders are "under control," Agerton still worries about how long they will plague him.