- A new study finds people who had COVID-19 may be more likely to experience cognitive decline over the following year.
- Researchers studied people over age 60 and found those who experienced more severe symptoms also showed greater impairment.
- Severe COVID-19 cases were associated with increased risk of early-onset, late-onset, and progressive cognitive decline.
“It is not surprising that individuals with more severe manifestations of COVID suffer some cognitive effects after their disease,” said Dr. Carl J. Fichtenbaum, clinical professor at the University of Cincinnati College of Medicine, speaking with Healthline.
Study findings show that 12.5 percent of COVID survivors demonstrated cognitive impairment 12 months after being hospitalized.
Those who experienced more severe symptoms also showed greater impairment than seniors who had milder cases of the disease.
The study included more than 3,200 participants ages 60 years and older who were discharged from the hospital between Feb. and April 2020.
The study excluded anyone who had pre-existing cognitive issues or a family history of dementia.
Researchers monitored the remaining 1,438 survivors and 438 controls at 6-month intervals by telephone interview. They included the uninfected spouses of these survivors as a control group.
Severe COVID-19 cases were associated with an increased risk of early-onset, late-onset, and progressive cognitive decline.
Milder cases were only associated with an increased risk of early-onset decline.
“The findings suggest that long-term cognitive decline is common after SARS-CoV-2 infection, indicating the necessity of evaluating the impact of the COVID-19 pandemic on the future dementia burden worldwide,” the study authors wrote.
“Several well-designed studies with large sample sizes provide consistent and convincing evidence that COVID-19 is associated with cognitive impairment,” said Abhishek Jaywant, PhD, a neuropsychologist at Weill Cornell Medicine.
He said there’s evidence to suggest that COVID-19 affects certain cognitive abilities more than others.
“Both from research and my experience working with patients, the cognitive deficits that are most common are changes in concentration, slowed processing, and difficulties with ‘executive functions’ — cognitive abilities like multitasking, ignoring distractions, and holding a lot of information in mind at once,” Jaywant said.
Jaywant explained that this “constellation” of cognitive difficulties is what COVID-19 survivors often describe as “brain fog.”
He noted that this includes younger populations.
“Our own research at Weill Cornell Medicine in hospitalized survivors of COVID-19 demonstrates that adults younger than 60 can experience cognitive impairment,” Jaywant said.
“This pandemic has impacted individuals in nearly all aspects of life,” said Dr. Paul Poulakos, a board certified psychiatrist in Greenwich Village, New York.
“Yet for older adults being a population at risk, their restrictions and routine alterations have had a profound impact on their mental health,” he continued.
Poulakos explained that cognitive decline in older adults is viewed largely in the context of “co-occurring psychiatric disorders,” like depression, anxiety, and addiction.
“Although there was a large push to increase access to mental/physical healthcare via telehealth during the pandemic, it is unclear whether or not this increase to access was appreciated by older populations,” he said. “Many of whom do not have access to such platforms or the skills to navigate the technology required.”
Fichtenbaum said the study raises many concerns and questions but points to flaws that “challenge the conclusions.”
He noted other issues with this research. For one, he said that cognitive assessment and retrospective collection of data make the strength of conclusions a “bit less believable.” He added that most studies of cognitive impairment require a battery of tests that are done in person and validated.
But Fichtenbaum considered the “repeated longitudinal follow up” of the participants over 12 months and with repeated evaluation a strong point of the study.
According to experts, the study design has flaws that raise unanswered questions.
“For example, is it just the severity of illness that is the problem or this virus?” Fichtenbaum asked.
He explained that the study authors should have compared individuals of the same age and sex who were hospitalized with other serious problems or non-COVID infections as a control group.
“Using spouses as a control may not be optimal because they did not experience disease and/or hospitalization,” Fichtenbaum said.
Researchers in China found that seniors who survived COVID-19 infection, regardless of if their symptoms were mild or severe, experienced an increased risk of cognitive decline.
Experts say the pandemic was highly disruptive to our lives, and it’s difficult to say if the cause was the virus itself or conditions created by pandemic restrictions.
They also say following CDC guidelines and being vaccinated are ways to reduce infection risk to minimize the odds of experiencing this condition.