One-fifth of Covid-19 patients get a psychiatric diagnosis within 90 days, study suggests
Posted November 9, 2020 6:33 p.m. EST
CNN — People who have had Covid-19 may have an increased risk of being diagnosed with a psychiatric disorder such as anxiety or depression, according to a new study.
Researchers looked at the medical records of 69 million people in the United States between January 20 and August 1. The data included 62,000 people who contracted Covid-19, as part of what the authors described as the largest study so far on links between coronavirus and mental health challenges.
In the three months following testing positive for Covid-19, almost one in five survivors (18%) were found to get a psychiatric diagnosis. This is about twice as likely as for other groups of patients with different illnesses and conditions analyzed as part of the study over the same period.
The researchers from the University of Oxford compared psychiatric diagnoses in Covid-19 survivors with patients who had influenza, other respiratory tract infections, skin infections, large bone fractures, gallstones and kidney stones.
"The study reports that patients have a somewhat higher risk of being diagnosed with a psychiatric illness, mainly anxiety or depression, after a COVID-19 diagnosis than after certain other medical events," said David Curtis, retired consultant psychiatrist and honorary professor at University College London and Queen Mary University of London, in a statement.
"For example, they show that there is an 18% chance of getting a psychiatric diagnosis after Covid-19 compared with 13% after influenza," Curtis, who wasn't involved in the research, told the Science Media Centre in London.
"It's difficult to judge the importance of these findings. These psychiatric diagnoses get made quite commonly when people present to doctors, and it may be unsurprising that this happens a bit more often in people with Covid-19, who may understandably have been worried that they might become seriously unwell and who will also have had to endure a period of isolation."
The study, which published in the journal Lancet Psychiatry on Monday, didn't look at the reasons or mechanisms that could explain the link between contracting Covid-19 and a psychiatric diagnosis.
It could be explained by several factors including a direct neurological or biological effect of the virus, the drugs used to treat it, the worry and anxiety caused by contracting the disease and wider concerns about the pandemic, said study author Paul Harrison, a professor of psychiatry at the University of Oxford and Warneford Hospital.
It's also possible that the data in the electronic medical records collated by the TriNetX Analytics Network didn't adequately capture socioeconomic or behavioral factors that might explain the link.
"We need to be cautious in our interpretation and unpick this important question," Harrison said in a news briefing.
Need for long-term data
In the period between 14 and 90 days after a Covid-19 diagnosis, 5.8% of survivors in the study had their first recorded diagnosis of psychiatric illness compared with 2.5% to 3.4% of patients in the comparison groups. Thus, adults have an approximately doubled risk of being newly diagnosed with a psychiatric disorder after a Covid-19 diagnosis, the study said.
Having a psychiatric disorder in the previous year was linked with an increased chance of getting Covid-19, the study also found. This risk was independent of known physical health risk factors for Covid-19, such as obesity, but could be explained by possible socioeconomic factors.
The researchers did not include mental health symptoms that appeared during the first two weeks such as delirium or other transient cognitive impairments. Other studies have found that delirium and agitation may be common in hospitalized coronavirus patients.
Medical experts said that the study had limitations. In particular, the follow-up period was only 90 days.
"Does distress persist when there is no life threatening infectious disease proliferating? This study does not offer long-term data -- this should be at the forefront of our minds when interpreting the findings -- it cannot predict psychiatric outcomes at one year follow up and does not account for worrying post-covid physical symptoms that may be distressing," Jo Daniels, a senior lecturer in clinical psychology at the University of Bath in the United Kingdom, told the SMC.
The study, Daniels said, didn't note what proportion of Covid survivors in the study had ongoing long Covid symptoms, which are known to be associated with disabling and distressing symptoms.
Dame Til Wykes, the vice dean of psychology and systems sciences at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, said we needed to develop as many different, accessible forms of mental health support as possible.
"We know from previous pandemics that mental health difficulties usually follow in survivors, and this study shows the same pattern after Covid-19, so it is not unexpected. But, though this is not a new finding, the data and the care with the analysis gives us more confidence in their results."