People with coronavirus infections, including Covid-19, may experience psychiatric problems while hospitalised and potentially after they recover, new research suggests.

Scientists looked at studies of people hospitalised by recent coronaviruses, namely Sars in 2002-2004, Mers in 2012, as well as Covid-19 this year.

According to the analysis, one in four people hospitalised with Covid-19 may experience delirium during their illness, a known problem among hospital patients, which can increase risk of death or extend time in hospital.

The post-recovery effects of Covid-19 are not yet known, researchers say.

Therefore, long-term risks such as post-traumatic stress disorder (PTSD), chronic fatigue, depression, and anxiety are based on Sars and Mers studies, which may or may not apply to the current virus as well.

Co-lead author Dr Jonathan Rogers, University College London Psychiatry, and South London and Maudsley NHS Foundation Trust, said: “Most people with Covid-19 will not develop any mental health problems, even among those with severe cases requiring hospitalisation, but given the huge numbers of people getting sick, the global impact on mental health could be considerable.

“Our analysis focuses on potential mental health risks of being hospitalised with a coronavirus infection, and how psychiatric conditions could worsen the prognosis or hold people back from returning to their normal lives after recovering.”

The authors of the new paper, published in The Lancet Psychiatry, analysed 65 peer-reviewed studies and seven recent pre-prints that are awaiting peer review.

These included data from more 3,500 people who have had one of the three related illnesses.

The research was led by the UCL Institute of Mental Health with King’s College London as collaborators.

It found that almost one in three people hospitalised with Sars or Mers went on to develop PTSD, at an average follow-up time of almost three years.

Rates of depression and anxiety were also high, with roughly 15% one year or longer after the illness, with a further 15% also experiencing some symptoms of depression and anxiety without a clinical diagnosis.

More than 15% of the patients experienced chronic fatigue, mood swings, sleep disorder, or impaired concentration and memory.

When data for patients with Covid-19 were examined, the scientists found evidence for delirium in 26 of 40 intensive care unit patients, and agitation in 40 of 58 intensive care unit patients in one study.

They further found altered consciousness in 17 of 82 patients who subsequently died in another study.

The study also identified some of the risk factors associated with worse mental health outcomes.

Senior author Professor Anthony David, UCL Institute of Mental Health, said: “To avoid a large-scale mental health crisis, we hope that people who have been hospitalised with Covid-19 will be offered support, and monitored after they recover to ensure they do not develop mental illnesses, and are able to access treatment if needed.

“While most people with Covid-19 will recover without experiencing mental illness, we need to research which factors may contribute to enduring mental health problems, and develop interventions to prevent and treat them.”

The research was supported by Wellcome, the National Institute for Health Research, and the Medical Research Council.