"For anxiety and depression, dealing with the stress of knowing you got COVID, having to isolate, worrying about your job, your future, your health, that's the most likely explanation for those diagnoses."

The theory that external circumstances are mostly to blame for mental health conditions in COVID-19 patients is somewhat confirmed by another of Harrison's findings. There was no significant difference in the number of people with anxiety and depression found in patients with mild COVID-19, those who had to go to the hospital and those who had to be placed in intensive care units.