New research out of Harvard has suggested a link between pre-existing psychological distress and long COVID.
The study, published September 8th in JAMA Psychiatry, found that people who exhibited symptoms of depression, anxiety, worry about COVID, loneliness, and perceived stress, were more likely to develop long COVID after infection than those who did not experience psychological distress.
They were also more likely to experience impairments in daily life up to a year after being infected.
Long COVID has been associated with reduced quality of life and an inability to return to work and systematic reviews, primarily of hospitalised patients, have estimated that 54% to 73% of patients may experience the condition.
Lead author, Dr Siwen Wang, from Harvard’s T.H. Chan School of Medicine, explained that psychological distress was already associated with greater severity and longer duration of acute respiratory tract infections.
“However, only 3 studies had previously examined psychological factors as potential risk factors of post–COVID conditions,” Dr Wang said.
“We found pre-infection psychological distress, including symptoms of depression, symptoms of anxiety, worry about COVID, loneliness, and perceived stress, was strongly associated with risk of long COVID among those infected.
“We found a dose dependent association between number of types of distress and risk of post–COVID conditions, with participants who experienced high levels of 2 or more types of distress at nearly 50% greater risk of developing long COVID than those who did not experience a high level of distress.
“These associations remained significant after further adjustment for health-related factors.”
Between April 2020 and November 2021, 54, 960 participants from three large ongoing US studies (Nurses’ Health Study II, Nurses’ Health Study 3, and the Growing Up Today Study) were periodically surveyed on their levels of distress and current COVID status.
COVID infection was self-reported every six months, with follow-up questionnaires issued quarterly, and related symptoms lasting four weeks or longer – as well as any impairment in daily life due to these symptoms – were self-reported on the final questionnaire, one year after baseline.
More than 3,000 participants (6%) reported a positive test result during follow-up (1-47 weeks after baseline) and among these, probable depression, probable anxiety, worry about COVID, perceived stress and loneliness were all associated with long COVID (1403 cases) in generalized estimating equation models – even after adjustment for sociodemographic factors, health behaviours, and comorbidities.
All types of distress were associated with increased risk of daily life impairment (783 cases) among individuals with long COVID conditions.
“However, our results should not be misinterpreted as supporting a hypothesis that post–COVID conditions are psychosomatic,” Dr Wang said. “First, among respondents who developed long COVID, more than 40% had no distress at baseline.
“Second, symptoms differ substantially from symptoms of mental illness. Although fatigue and brain fog may occur with depression, smell and taste problems, shortness of breath and difficulty breathing, and cough are not common symptoms of mental illness.
“Third, more than 50% of patients with long COVID report relapses triggered by physical activity, whereas physical activity is actually protective against a relapse of mental illness, and finally, results were similar when excluding participants reporting only psychiatric, cognitive, or neurological symptoms.”