A serious bout of COVID-19 can prompt a serious loss of brain power, new research warns, triggering a drop in IQ that's equivalent to aging from 50 to 70 in a matter of months.
"Previous research has indicated that people who have recovered from COVID-19 may suffer from lasting problems in terms of their ability to concentrate and problem solve," noted study author Adam Hampshire. He's an associate member with the U.K. Dementia Research Institute Care Research and Technology Centre, in London.
"What we were trying to find out was how pronounced these [thinking] difficulties were in patients who had been more severely ill, which aspects of [thinking] were most affected, whether there was any sign of recovery over time, and what the underlying cause might be," Hampshire added.
To that end, the research team focused on a group of 46 British patients who had been hospitalized with severe COVID-19 during the first few months of the pandemic (from March 2020 through July 2020). At the time, one-third had been so sick that they needed to be put on a mechanical ventilator.
Mental health assessments conducted six months after first being hospitalized - at which point the initial viral infections had resolved - revealed a significant drop in memory and concentration skills, alongside a notable slow-down in the ability to problem-solve accurately and quickly.
Patients were often very forgetful, Hampshire stressed, struggling with the sort of "brain fog" that would often make it difficult to find the words to express themselves.
All told, the study team found the diminished post-COVID brain capacity would likely translate into a 10-point drop in IQ.
Hampshire, who is also a professor of restorative neurosciences in the department of brain sciences at Imperial College London, said that although he had expected to see some degree of lingering brain performance issues, he was "surprised by the scale of the [thinking] problems that the patients had."
"The level of [thinking] under-performance is similar to that seen when aging from 50 to 70," he noted.
Normally, "a person slows down substantially during those two decades," Hampshire said. "But they also have a lot of time to adjust. For these patients, it must come as a sudden shock. I expect that some of them may not ever fully recover or be able to return to work."
So far, he said, recovery has been "so slow as to be statistically non-significant. That is, we could not confirm that there was any cognitive recovery over time, though at least a trend was there."
As for what's going on, Hampshire acknowledged that the jury is still out.
"The cause remains to be determined," he said. "But our study indicates that it is more likely to be something that happens during the initial illness as opposed to mental health problems, such as depression and anxiety, after recovery. That is, the patients also show signs of depression, anxiety and post-traumatic stress, but these appear to be separate to the [thinking] problems."
Going forward, Hampshire said it will be important to continue to track such patients over a longer period of time to see who recovers, or if recovery is even possible. Meanwhile, however, "the truth is at the moment we do not know what will help them."
The findings were published in the May issue of the journal eClinicalMedicine.
Dr. Colin Franz, a physician-scientist with the Shirley Ryan AbilityLab in Chicago, said the findings dovetail with his own experience with COVID-19 survivors.
"As a physician who regularly sees people post-COVID, I am not surprised that there are persistent mental health issues like memory or concentration in the months after hospitalization," he said. "This is one of the more common concerns our 'long-COVID' patients bring to us."
The precise reason may vary from patient to patient, added Franz, who was not involved in the study.
"For example, in one person it could be connected to an issue with the very small blood vessels in the brain," he noted. "But in another one, they have persistent breathing issues that disturb sleep and increase fatigue that may play into poor test performance."
Franz's advice for those with persistent brain health issues post-COVID "is to seek help from a well-coordinated, and comprehensive post-COVID clinic in your area," whether that be an outpatient therapy program or a personal doctor.
There's more detailed information on the long-lasting impact of COVID at the American Psychological Association.
SOURCES: Adam Hampshire, PhD, associate member, UK Dementia Research Institute Care Research and Technology Centre, and professor, restorative neurosciences, department of brain sciences, Imperial College London; Colin Franz, MD, PhD, physician-scientist, Shirley Ryan AbilityLab, Chicago, and assistant professor, physical medicine and rehabilitation and neurology, Feinberg School of Medicine, Northwestern University, Chicago; eClinicalMedicine, May 2022, online