A new study has investigated the relationship between COVID-19 and psychiatric illness. The study’s authors say that their findings suggest that a diagnosis of COVID-19 increases the risk of subsequent psychiatric illness. In turn, people with a psychiatric diagnosis were found to be at an increased risk of contracting COVID-19. Questions remain about whether the increased risk is due to a disease mechanism or other contributing factors.
The study, published in The Lancet Psychiatry by researchers from the University of Oxford, used electronic health record data from over 62,000 COVID-19 cases reported from across 54 healthcare organizations in the US.
The authors compared the rates of psychiatric conditions, such as anxiety disorders and psychotic disorders, in the 14 to 90 days after a COVID-19 diagnosis and compared them with six other health events, such as other respiratory tract infections and gall stone formation.
Nearly 1 in 5 receive psychiatric diagnosis
The researchers say that the incidence of a psychiatric diagnosis in the period analyzed was 18.1%. This was higher compared to that of other conditions included in the analysis. The corresponding hazard ratios varied between 1.58 and 2.24. Reacting to the paper, Prof. Dame Til Wykes, vice dean of psychology and systems sciences at the Institute of Psychiatry, Psychology and Neuroscience, King’s College London, said, “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.”
The authors controlled for various other factors that might have contributed to a psychiatric diagnosis, such as housing status. In all cases, the significance of the results held. However, the authors acknowledge that some socioeconomic factors will not have been captured in their analysis. Speaking to Technology Networks, first author Maxime Tuquet, an academic clinical fellow at the University of Oxford, suggested that household income would be an uncontrolled dimension that may influence the findings. “We used extreme levels of poverty (which includes things like being homeless) as a confounding factor (which we had access to in the dataset) but clearly this only captures the most extreme levels of socioeconomic deprivation.”
In turn, diagnosis with a psychiatric disorder was linked to an increased risk of COVID-19. The risk, say, the authors, increased by 65% after such a diagnosis. This increased risk was still seen if the authors excluded all the patients in their analysis with selected other COVID-19 risk factors, such as obesity.
Calls for caution
Some academic reactions to the paper called for caution in interpreting the study’s findings. “Psychiatric outcomes are measured up to 90 days post-infection only, and we are not made privy to what proportion have ongoing long COVID symptoms, which is known to be associated with disabling and distressing symptoms – this is highly pertinent to interpretation,” said Dr Jo Daniels, a senior lecturer in clinical psychology at the University of Bath. Tuquet agreed that long COVID-19, where symptoms such as fatigue and shortness of breath persists for weeks or even months after recovery from acute illness, is an important factor to pay attention to but is one that is not yet properly defined.
It remains unclear whether the increased risk of psychiatric disease is due to a disease process or rather the uniquely stressful experience of being diagnosed with a novel viral infection with few existing treatment options. Daniels addressed this latter possibility in a statement: “It is reasonable to expect psychological distress that persists for some time following a significant health threat, particularly if over a period when stay at home orders or lockdown procedures are in place.” Tuquet agreed that this could be an explanation for the increased rate of anxiety disorders noted in the study, but said that the message to COVID-19 patients worried about psychiatric symptoms should be that “these are treatable illnesses for which they can seek medical support.”