The systematic review paper, published in The Lancet Psychiatry, compiled results from short- and long-term studies of people hospitalised by recent coronaviruses, namely SARS (Severe acute respiratory syndrome) in 2002-2004, MERS (Middle East respiratory syndrome) in 2012, as well as COVID-19 this year.
COVID-19 is caused by the SARS-CoV-2 virus, a type of coronavirus. Some coronaviruses only cause mild symptoms of the common cold, but SARS-CoV-2 can cause severe respiratory illness, as did SARS-CoV-1 (the virus implicated in the 2002-2004 SARS epidemic) and MERS-CoV, which caused MERS in 2012.
The analysis found that 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, so 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 COVID-19 as well.
Co-lead author Dr. Jonathan Rogers (UCL 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 analysed 65 peer-reviewed studies and seven recent pre-prints that are awaiting peer review, which included data from over 3,500 people who have had one of the three related illnesses. The review only included results from people who were hospitalised, and not people with more mild cases. The findings cover both acute symptoms during the illness, and long-term outcomes from 2 months to 12 years.
Almost one in three people hospitalised with SARS or MERS went on to develop PTSD, at an average follow-up time of almost 3 years, especially if they had ongoing physical health problems. Rates of depression and anxiety were also high, at 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% also experienced chronic fatigue, mood swings, sleep disorder or impaired concentration and memory.
While in hospital, a significant minority of people with coronavirus infections experienced delirium symptoms such as confusion, agitation and altered consciousness. Almost 28% of people hospitalised for SARS and MERS experienced confusion, and early evidence from the ongoing pandemic suggests that delirium could be similarly common in COVID-19 patients. The authors found some preliminary evidence that delirium may have been associated with raised mortality during the MERS outbreak.
Co-lead author Dr. Edward Chesney (Institute of Psychiatry, Psychology & Neuroscience, King's College London and South London and Maudsley NHS Foundation Trust) said: "We need more research on how to prevent mental health problems in the long term. One possibility might be to reduce social isolation by allowing patients to communicate with their loved ones by using video links."
The body of research also identified some of the risk factors associated with worse mental health outcomes. Researchers found that worrying a lot about the illness was associated with worse mental health in the long run, and healthcare workers had worse long-term mental health outcomes than other groups, while making a good physical recovery predicted better long-term mental health.
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."