Although COVID-19 is largely thought to be a respiratory disease, doctors believe it also affects the nerve system, causing severe neurological symptoms in rare cases. Some COVID-19 survivors have long-term mental health issues, such as anxiety, depression, and post-traumatic stress disorder.
The previous studies have looked at functional brain abnormalities, which could explain the physiological processes behind long-term mental health issues in COVID-19 survivors.
In this new study, published in Neurobiology of Stress, the researchers set out to investigate whether survivors had functional disruption of large-scale brain networks, which are groupings of discrete and extensive parts of the brain that work together to complete complex cognitive tasks.
They gathered functional MRI (fMRI) data as well as self-reported post-traumatic stress symptoms from 50 COVID-19 survivors and matched control participants. The COVID-19 survivors were discharged from hospitals in Wuhan, China, during February and March 2020, and were tested roughly six months later.
The results of the study found that COVID-19 survivors self-reported considerably more symptoms of post-traumatic stress disorder than controls. The study also discovered that COVID-19 survivors had aberrant patterns of brain connection over time, which were strongly associated with higher levels of post-traumatic stress symptoms.
The researchers discovered three unique, recurring states of functional connectivity in the brains of the participants. The COVID-19 survivors had a higher occurrence of a certain condition characterised by patterns of connections between brain networks including sensory functions and visual networks.
“When we looked within the COVID-19 survivor group, we also found a significant relationship between the severity of their post-traumatic stress symptoms and how often their brain patterns are in that state,” said the study author.
“If they spend more time in that state, they tend to have higher values on those symptom scales.”
“Our findings provide evidence that COVID might affect transient brain dynamics rather than its ongoing activity,” said the study’s first author.
The findings emphasize the necessity of assessing transient, time-varying functional network changes in COVID-19 survivors, however, the study authors caution that many things remain unresolved, including why this single brain state is associated with post-traumatic stress disorder.
The research team would also like to replicate the study using different data and examine changes in subjects before and after contracting COVID-19.
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