People Are Experiencing Brain Fog Long After COVID-19 Recovery

For some people, COVID-19 symptoms remain weeks or even months after the infection has gone—a condition known as post-COVID-19 syndrome or “long COVID.” The lingering symptoms aren’t the same for everybody, but many patients report memory lapses, difficulty concentrating and other cognitive issues, commonly referred to collectively as “brain fog.”

A new study, published in the journal JAMA Network Open, found that some people are experiencing brain fog several months after surviving COVID-19–both those who were severely ill and hospitalized with the infection, and those who reported only mild symptoms.

A Closer Look at the Study 

Researchers led by Jacqueline Becker, PhD, a neuropsychologist at the Icahn School of Medicine at Mount Sinai in New York City, assessed 740 patients with a history of COVID-19 who were being followed up through a Mount Sinai registry. On average, more than seven months had passed since the patients had been infected with COVID-19.

Those who'd been hospitalized were more affected. Almost a third of the patients showed impairment on several memory tests, while nearly one-quarter of them had difficulties with executive functioning (planning, organization, and other mental skills routinely used to accomplish daily tasks). 

Still, between 15% and 24% of people who'd stayed home during their COVID-19 infection displayed memory or executive functioning impairments. 

While cognitive impairment is typically associated with older people, the researchers found that many of these patients were relatively young—the average age was 49–and otherwise in good health and free from conditions like diabetes and high blood pressure. 

“It is well known that individuals can sustain cognitive deficits after critical illness, particularly older adults and those with other comorbid diseases,” says Dr. Becker. “Our findings were surprising in that we did not expect to see such a high frequency of cognitive impairment in a relatively young cohort, nor in those who had only mild COVID-19.” 

What’s the Link Between COVID-19 and Brain Fog?

When it comes to the cognitive dysfunction that many survivors of COVID-19 experience, there’s still a great deal of uncertainty.

“Because this is all a relatively new phenomena the overall understanding continues to evolve,” says Scott Kaiser, MD, board certified geriatrician and Director of Geriatric Cognitive Health for the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, California.

According to Dr. Kaiser, there are many potential pathways—reduced oxygen delivery, reduced blood flow, an attack by the immune system on healthy brain cells, an actual invasion of infectious cells into the brain, or inflammation affecting brain cells. “A combination of multiple factors may actually be at play, plus additional factors associated with having COVID-19 may indirectly contribute as well, like increased stress and anxiety, depressed mood, changes in diet, medications, decreased physical activity, poor sleep quality, or even social isolation and feelings of loneliness,” he explains. 

It’s also possible that certain cases have different causes. But overall, there does appear to be a clear physiological pathway by which infection with the virus induces an inflammatory response that actually causes inflammation in the brain—neuroinflammation—which can, in turn, can cause cognitive dysfunction, Dr. Kaiser says. 

New research like the Mount Sinai study helps to increase our understanding of this phenomena.   

“This study reinforces the idea that the experience of cognitive impairment following COVID-19 is quite frequent and is striking in the extent to which this impairment may persist for many months following infection, even in cases that were not that severe,” Dr. Kaiser says. 

Managing Brain Fog 

As far as the true long-term consequences of long COVID brain fog go, Dr. Kaiser believes it’s just too soon to tell. “While it appears that most cases gradually resolve—even if it takes several months—it’s unclear if a subset of people may continue to have lingering symptoms across an even longer time horizon,” he says. “Similarly, it remains unknown whether or not this could actually increase one’s ultimate risk of a major neurocognitive disorder—dementia—later in life.” 

If you're experiencing brain fog, it's important to seek help from a primary care physician. This may involve a referral to a neuropsychologist in order to rule out other, potentially reversible causes of cognitive impairment, like depression. 

"There are now many specialty resources available to support people experiencing prolonged COVID-19 symptoms and there may be opportunities to better understand the nature of an individual’s cognitive dysfunction and tailored strategies to address this," says Dr. Kaiser. 

For good overall brain health, he recommends a brain healthy (anti-inflammatory) diet, physical and cognitive exercise, sufficient sleep (in terms of quantity and quality), healthy social connections, creative engagement, stress management, and other components of good self-care.

Lots of strategies may help you mitigate the impact of post-COVID-19 brain fog in everyday life. Dr. Becker suggests writing things down in a notebook, setting reminders for important tasks, focusing on one task at a time rather than multitasking, taking short breaks as needed, and breaking down overwhelming tasks into manageable chunks.