It's been a common refrain among Talee Vang's patients.

The senior clinical psychologist at Hennepin Health Care has repeatedly heard them talk about struggling to stay on task, being irritable and forgetful.

Vang chalks it up to brain fog, a side effect of the pandemic.

"I'd say it's a response to our collective fatigue, the chronic stress we've all been dealing with," she said. "People are on edge and it takes a toll on the way they think."

As we come out of an unprecedented year of changes and isolation, the term is being used to refer to a constellation of symptoms that include a lack of concentration, motivation and enthusiasm.

The phenomenon — which is affecting those who have had COVID as well as those who haven't — is attracting attention from academics, medical researchers and mental health professionals who are trying to understand exactly what brain fog is and whether it will fade as fast as toilet paper shortages or prove to be more persistent.

In addition to hearing about brain fog from her patients, Vang admits she's seeing signs it in some of her colleagues — and herself.

The mother of four children under age 12, Vang worked from home for part of 2020. She blames some of her fuzziness on the disruptions that put everyone's brain on overload.

"When you work and learn from home, there's no differentiated space," she said. "We work and relax in the same confined rooms and we're there on weekends, too. With no place to decompress, we carry the stressors with us."

Vang isn't the only one who's noticed it. Articles that analyze brain fog as part of the cognitive changes connected to COVID-19 are popping up in scientific journals.

Researchers at the University of Minnesota are exploring its implications, as well.

Psychology professor Richard Lee was in the midst of a longitudinal study on mental health in students, staff and faculty at the university. In April 2020, he and his colleagues shifted to tracking well-being during the pandemic, adding questions specifically about mental acuity. Up to 20% of respondents reported a drop in clarity of thinking.

"They self-report about having a harder time focusing, communicating, concentrating and staying motivated," he said about study participants. "They talk about a lack of enthusiasm, trudging through the day. COVID brain fog is just starting to be documented in the literature, but it's a real thing."

Lee and his collaborators plan to eventually submit their findings for publication in a scholarly journal. In the meantime, they have made presentations to administrators at the university.

"Symptoms of forgetfulness and a slowdown in thought-processing speed have huge implications for students, but this is also a factor in the workforce of the knowledge economy," he said.

"With brain fog, there could be more errors or difficulties getting things done on time. Employers may have to adjust performance standards. They will have to consider whether to be gracious or to penalize people who can't hold to the same standards as before."

A COVID side effect?

Although brain fog isn't a medical term, neurologists have long studied the phenomenon in other contexts.

Scientists have verified a change in concentration, blurred memory and dysfunction in thinking associated with chemotherapy ("chemobrain"). And there is a growing body of research about "baby brain," a change in cognitive and executive function experienced by some pregnant women and new mothers.

Impaired thinking also has been linked to the COVID-19 diagnosis in some people.

Melissa Gerads Jones blamed brain fog for her difficulty holding her own in a conversation and her ability to remember things, like a favorite recipe.

"I've been kicking it out for years from memory," she said of a dish called Glow-in-the-Dark Chicken because of its reliance on turmeric. "It has a lot of steps and seasonings in varying amounts and I could not for the life of me remember what they were and how much to use. It was quite upsetting."

Jones' brain fog is likely connected to COVID-19, which she contracted in March 2020 and couldn't shake. Because of her lingering congestion, chest pain, wheezing and fatigue she's been treated at the Mayo Clinic as a so-called long hauler.

Rehabilitation physicians from Mayo have created a podcast and YouTube videos to explain brain fog as a common side effect in long-haul patients, noting that puzzling cognitive symptoms plague these recovering COVID-19 patients long after the virus cleared their system.

"I consider myself a nimble thinker, a multitasker, but I've had to think so hard about everything," Jones said. "I had a hard time following conversations. It's like wading through pudding."

Since receiving her second vaccine, Jones has felt the fog begin to lift, but only after the Minneapolis mother of two teenagers spent more than a year struggling to stay on top of their remote learning while logging into her job from her dining room table.

"I think my fog was exacerbated by working from home," she said. "Seems like we all have to work harder to do the things we do."

Nebulous trauma

For some people, brain fog has altered their spiritual practices.

"When survival mode kicked in, we put our heads down to get through every day," said the Rev. Natalia Terfa. "For many people of faith, that didn't leave the mental space required to think deep theological thoughts. It's been hard to set aside time to pray or think about God."

Terfa, the pastor at Prince of Peace Lutheran Church in Brooklyn Park and host of a popular Christian podcast, sees a sort of spiritual fog interfering with the quest to find meaning during challenging times.

"Many of us don't recognize what we are feeling as grief. When there's loss or a cancer diagnosis or divorce, we lean into our faith. But the nebulous trauma of the pandemic is hard to name," she said. "We experience God through the community we're part of. Not being able to connect creates distance. And the further we get from faith, the harder it can be to walk back to it."

Terfa is curious to learn if a return to in-person services may ease some of the spiritual alienation.

Vang also wonders how she and the people she counsels will emerge from the brain fog of the pandemic.

She's advising her patients to get adequate sleep to nourish brain function, to manage and limit screen time and to prioritize summer days to take breaks and seek a change of scenery to jump-start thinking patterns.

"I tell patients to utilize PTO days," she said. "I encourage them to get outside, go fishing or on a picnic. For parents, it's helpful to take a day when kids are busy; spend time by yourself or with your partner," she said. "Once things settle and we know what the future will look like, we can adjust and readjust.

"I try to follow my own advice," she said. "I think it helps."

Kevyn Burger is a Minneapolis-based freelance broadcaster and writer.