At this point, it’s obvious that the stress of life with Covid-19 has caused a decline in our collective mental health. Now new research suggests pandemic-induced stress has fundamentally altered some people’s brains.
The discovery adds to a body of research on what causes accelerated brain aging, which we know is influenced by both biological and environmental factors. The brain’s appearance changes as people age, but the evidence suggests not all people experience brain aging at the same rate. Stressful events can cause a mismatch between a person’s brain age and their chronological age — how many years they’ve been alive.
In a recent study, scientists examined how adversities related to the pandemic — social isolation, financial strain, and threats to physical health — influenced the brains of young people living in the San Francisco Bay Area during the lockdowns of 2020. Overall, the adolescents appeared to have brain features more typical of older people — and those who experienced serious adversity in childhood.
Compared to young people assessed before the pandemic, the study participants’ brains had reduced cortical thickness, larger hippocampal and amygdala volume, and more advanced brain age. Their mental health was also worse, but it’s unclear whether their mood and changes in brain structure are linked.
Although several studies, including this one, establish a relationship between early life stress and accelerated brain aging, it’s not obvious what drives the connection. But the cortisol secreted in response to stress may play a role, Ian Gotlib tells me. Gotlib is a professor at Stanford University and the new study’s first author.
Importantly, it’s an open question whether or not these changes are permanent. But one can take action to safeguard brain health despite the stress.
“We don’t know if the effects can be reversed,” Gotlib says. “But I expect that stress-reduction techniques, like meditation, relaxation, etcetera, can slow the rate of brain aging.”
How stress physically changes the brain
Before Covid-19 hit, Gotlib and his colleagues were about three-fourths of the way through a longitudinal study of the effects of early life stress on trajectories of brain development and depression in adolescents. The pandemic initially interrupted their work, but it ultimately presented an opportunity: The scientists could compare pre-pandemic brain scans to scans taken at the end of 2020.
The team matched adolescents by age, gender, exposure to stress, and socioeconomic status and compared the before and after groups’ scans. Ultimately, they found that young people at the end of the first year of the pandemic had older brain ages than similar young people scanned before it started.
The findings imply that the pandemic negatively affected this group's mental health and accelerated brain maturation.
Scientists can’t say whether this group's chronological age will catch up to their brain age. But other studies suggest people with older-looking brains do worse on tests measuring attention, memory, and executive function.
There are actions people can generally take shown to strengthen cognitive health. These include:
- Managing high blood pressure
- Eating healthy foods
- Being physically active
- Coping with stress
Gotlib and his colleagues plan on following up with the participants when they’re 20 years old to “see whether the difficulties in mental health and the accelerated brain aging persist beyond the pandemic,” he says.