How Covid-19 Affects the Brain, During and After Sickness

The virus’s mental health impact may mean a secondary epidemic

Illustration: Simone Noronha

Once Katie Swanson’s lips and eyelids turned blue, she stopped being able to sleep. The 28-year-old has always been “great at sleeping,” she says — an early-to-bed and early-to-rise type of person — but the coronavirus had her oxygen levels cratering, and she knew they might drop more as she slept.

“I was too afraid because I thought I wasn’t going to wake up,” Swanson says. “I was fully convinced I would die in my sleep.” Weeks after the peak of her illness, she’s still restless. “Every single night I have to take melatonin now,” she says, and that doesn’t always work.

A profound anxiety around sleep is one of a long list of mental symptoms Swanson says she experienced alongside the physical ones as she battled a case of the coronavirus severe enough to hospitalize her twice. And while her breathing has improved considerably—and her face is now a normal shade—the mental recovery has been much slower.

“My memory is really bad,” the California native says. “For a while, I couldn’t think of really basic words or definitions. I went weeks without talking to anybody because it was too much work.” It’s much more than the “brain fog” that can often accompany a bad cold or flu: She compares it to having a severe concussion.

Swanson’s experience isn’t exceptional: It’s become clear that the virus that causes Covid-19 affects more than the lungs. Nearly 40% of people infected, a team of Chinese doctors recently wrote, “develop neurological symptoms, including headache, disturbed consciousness, and paresthesia.”

People with Covid-19 receiving critical care are at high risk of delirium, extreme confusion, or hallucinations. And severe illness, treatment, and recovery can leave lingering emotional trauma, raising the odds that a person will go on to develop anxiety, depression, or related conditions. But on top of all that, scientists are also beginning to understand that coronaviruses, particularly this one, have neurotropic properties, meaning the bug can attack the nervous system, entering the brain or the cerebrospinal fluid. The result may be neurological symptoms that accompany the infection, linger…