Mental health and neurological symptoms are experienced by many people with COVID-19, including those with a mild case of infection.
The findings are based on a study by researchers at University College London that looked at the most common symptoms experienced by people with COVID-19.
Researchers pooled data from 215 studies from 30 different countries, including over 100,000 cases in total.
When looking at the entire study population, which included all severities of infection, loss of smell, weakness, and fatigue were the three most common symptoms with 43%, 40% and 38% of all people experiencing them.
Depression and anxiety were also common, with 1 in 4 (23%) and around 1 in 6 (16%) people experiencing either, respectively.
Major neurological conditions were also noted, although they were far less common: ischaemic stroke (caused by a blood clot in the brain) occurred in 1.9% of cases, haemorrhagic stroke (caused by a bleed in the brain) in 0.4%, and seizure in 0.06%.
When looking specifically at milder cases of COVID-19, i.e. those with symptoms who were not hospitalised, neurological and psychiatric symptoms remained common: 55% experienced fatigue, 52% loss of smell, 47% muscle pain, 45% loss of taste, and 44% headaches.
The findings were not what the researchers expected, with the original belief being that the rate of mental health and neurological issues would be higher in more severe cases.
"We had expected that neurological and psychiatric symptoms would be more common in severe COVID-19 cases, but instead we found that some symptoms appeared to be more common in mild cases," said study lead author, Dr Jonathan Rogers.
"It appears that COVID-19 affecting mental health and the brain is the norm, rather than the exception."
The study was not an attempt at identifying the causes of COVID-19 symptoms, however the researchers do suggest some reasoning behind their findings.
One reason for mental health or neurological symptoms being common even in mild cases of COVID-19 could be inflammation of the brain, while a lack of interaction with family and friends and general attitude toward the virus could also drive symptoms like depression or anxiety.
The authors also found that most studies only looked at a small number of neurological symptoms while often disregarding symptoms of poor mental health –something the authors say needs to be investigated further for a better understanding of the virus' impact on mental wellbeing.
"Many factors could contribute to neurological and psychiatric symptoms in the early stages of infection with COVID-19, including inflammation, impaired oxygen delivery to the brain, and psychological factors," added Rogers. "More studies are needed to understand these links better."
To read more about the study, click here.
Written by Marco Ricci
Editor and contributor for Talking Mental Health