People who've had COVID-19 are facing memory problems months after contracting the disease, new study says: 'They can't think'

• A new study reveals that people who've had COVID-19 in the past may exhibit cognitive impairments months after an infection.
• Those impairments can include problems with memory, as well as slower processing speed.

People who've recovered from the coronavirus are experiencing problems with their memory, new research and data reveal.

A study, published Friday in medical journal JAMA Network Open, says nearly a quarter of individuals who've been infected with the coronavirus have problems retaining information and focusing months after contracting the disease. Researchers, examining 740 patients at the Mount Sinai Health System in New York, found that it's relatively common for people who've had COVID-19 before to struggle with things like multitasking.

"In this study, we found a relatively high frequency of cognitive impairment several months after patients contracted COVID-19. Impairments in executive functioning, processing speed, category fluency, memory encoding, and recall were predominant among hospitalized patients," Jacqueline Becker and other researchers at the Icahn School of Medicine at Mount Sinai in New York said, according to the study.

The patients were tested between April 2020 and May 2021, the study says. They were all at least 18 years old and had no history of dementia. Researchers found that the patients, about seven or eight months after having contracted the disease, exhibited signs of cognitive impairment.

That includes problems with memory recall and the ability to store new memories, the study says, as well as with making judgment calls and planning.

Some of these patients "cannot function," psychiatry professor Dr. Helen Lavretsky told NBC News. "They can't think; their memory is impaired; they get confused when they drive places, that they don't know how they got there."

The research showed that patients most likely to show signs of cognitive impairment had been hospitalized for COVID-19. But some patients who received treatment in the emergency department of the hospital also presented with a decrease in brain function.

One of the longterm effects of COVID-19 is "brain fog," or difficulty thinking and concentrating, according to the Centers for Disease Control and Prevention.

"Although most people with COVID-19 get better within weeks of illness, some people experience post-COVID conditions," the CDC website says. "Post-COVID conditions are a wide range of new, returning, or ongoing health problems people can experience four or more weeks after first being infected with the virus that causes COVID-19."