In a new study from the Hotel-Dieu hospital in Paris, researchers found that symptoms of so-called long COVID may be more due to psychological factors than to infection with the virus.
The team examined nearly 27,000 participants across France who took antibody tests to screen for COVID infection.
After the participants had received the antibody test results, the researchers asked them whether they believed they had been infected with COVID and to report on symptoms like fatigue, breathlessness or impaired attention.
Most of the respondents tested negative for COVID antibodies and believed they had never been sick. Of the 1,000 who tested positive, about 450 believed they had contracted the virus.
Finally, about 460 people who received negative antibody tests said they nonetheless believed they had had COVID.
The team found that people who believed they had had COVID, whether or not they had had a positive test, were more likely to report long-term symptoms.
But a positive antibody test, meanwhile, was only consistently associated with one long-term symptom: loss of smell.
The team says that persistent physical symptoms may be linked more to the belief in having been infected with SARS-CoV-2 than with having laboratory-confirmed COVID-19 infection.
They suggest the findings were important in order to allow research into other causes of the symptoms.
A medical evaluation of these patients may be needed to prevent symptoms due to another disease being erroneously attributed to ‘long COVID’.
The study is published in the Journal of the American Medical Association. One author of the study is Cedric Lemogne.
