Many COVID-19 survivors are likely to be at greater risk of developing mental illness, say psychiatrists after a large study found 20 per cent of those infected are diagnosed with a psychiatric disorder within 90 days.
Anxiety, depression and insomnia were most common among recovered COVID-19 patients in the study who developed mental health problems, and researchers also found significantly higher risks of dementia.
"People have been worried that COVID-19 survivors will be at greater risk of mental health problems and our findings ... show this to be likely," said Paul Harrison, a professor of psychiatry at Britain's Oxford University.
Doctors and scientists around the world urgently need to investigate the causes and identify new treatments for mental illness after COVID-19, Harrison said.
"(Health) services need to be ready to provide care, especially since our results are likely to be underestimates (of the number of psychiatric patients)."
The study, published in The Lancet Psychiatry journal, analysed health records of 69 million people in the United States, including more than 62,000 cases of COVID-19.
In the three months following testing positive, 1 in 5 survivors were recorded as having a first time diagnosis of anxiety, depression or insomnia.
This was about twice as likely as for other groups.
The study also found people with a pre-existing mental illness were 65 per cent more likely to be diagnosed with COVID-19 than those without.
Mental health specialists not directly involved with the study said its findings add to growing evidence COVID-19 can affect the brain and mind, increasing the risk of a range of psychiatric illnesses.
"This is likely due to a combination of the psychological stressors associated with this particular pandemic and the physical effects of the illness," said University College London's Michael Bloomfield.
Simon Wessely, regius professor of psychiatry at King's College London, said the findings echoed results studies of previous infectious disease outbreaks.