A high proportion of young Israeli adults who participated in a research study at Tel Aviv University have shown an increase in the volume of a part of the human brain that controls emotions known as the amygdala, following the first coronavirus lockdown.
Prof. Yaniv Assaf and his research team compared MRI scans of the brains of 75 healthy people in Israel under the age of 30 before and after the first coronavirus lockdown. They found that 95% of them showed an increase in the volume of the amygdala and a few other parts of the temporal lobes.
Assaf, a member of TAU’s Faculty of Life Sciences, the Sagol School of Neuroscience and head of the Strauss Center for Neuroimaging, said he and his team believe this volume increase in the brain region that plays a key role in processing emotions “is probably a brain expression of the uncertainty, anxiety and stress that the subjects experienced as a result of the outbreak of the pandemic and the closure.”
When the pandemic and the lockdown began, the researchers decided to contact subjects who had undergone MRIs between the fourth quarter of 2019 and February 2020 for other research, and they rescanned their brains after the lockdown ended, Assaf said. The team began the second round of scans in early May and continued them until recently.
The results showed that in the first post-lockdown scans, 95% of the subjects’ amygdala had increased in volume by more than 10%. Many had an increased volume of 12%-15%, but this volume diminished in subsequent scans to 2%-3% above normal, he said.
By contrast, a control group of scans done on healthy subjects several months apart in 2019, before the coronavirus outbreak, showed no increase in the volume of the amygdala.
The study is unusual because generally, when scientists examine the effect of stress on the brain, it is in response to an intensely traumatic event, such as a car accident, Assaf said. Coronavirus is different because it is a prolonged event “with relatively low intensity, but people go to sleep thinking about the virus and the lockdown, and they wake up thinking about it,” he said.
About 40% of the study’s participants were furloughed without pay during the lockdown, and this would likely have increased their anxiety about their financial situation and well-being, he said.
The researchers plan to rescan the subjects after the current lockdown and expect to see that 5%-10% will experience a post-traumatic stress response, which could result in a reduction of the amygdala volume.
“I suspect we’ll see more depression and despair after the second lockdown – whenever it’s over,” Assaf said.
Uncertainty and constantly changing regulations that many consider to be arbitrary could add to the stress people experience, he said.
“The Health Ministry and the government must take into account that mental health is as important as the effects of the virus... Even if 1% of the population is infected with the coronavirus, nine million people are affected by the stress,” Assaf said. “The virus will go away someday, but the mental-health effects will be with us for a long time.”
The research team has submitted a paper on its MRI scans to peer-reviewed journals and has posted a pre-publication version of its findings that has not been peer-reviewed online at:
https://www.biorxiv.org/content/10.1101/2020.09.08.285007v1.
“This pandemic has given us a unique opportunity to explore the effects of a prolonged stressful event on people,” Assaf said. “You could say that it’s the largest behavioral experiment in the history of the world... No one wanted to go through this, but can people go through it in a better way?”
Understanding the effects the lockdown has on mental health is a first step toward finding that better way, he said.