There are more than 250 of them. The symptoms of long Covid are numerous: intense fatigue, shortness of breath, chest pain, loss of taste and smell, difficulty concentrating … But does this long form of the disease actually stem from psychological springs? This is what suggests a study published Monday, November 8 in a leading scientific journal, the Journal of the American Medical Association (Jama). Since then, criticism from scientists and patients has multiplied. Franceinfo takes stock of what to remember from this survey.
>>> TESTIMONIALS. They have been fighting for months against the symptoms of a long Covid “which dictates their life”
What the study says
Nearly 27,000 adults, monitored for months by the French public health authorities to assess multiple effects of Covid, were interviewed as part of this study. They belong to the largest French epidemiological cohort, called Constances, which brings together 200,000 French volunteers aged 18 to 69 years.
The study suggests that, for a patient, the fact of having contracted Covid-19 is more strongly associated with prolonged symptoms several months after being exposed to the disease, than the fact of having had a positive result to a serological test. In other words: the investigation concludes that most of the symptoms associated with long Covid are more related to claiming to be a former patient than to having been infected, even if these two situations overlap in most cases.
Except for anosmia, persistent symptoms after COVID-19 may be more related to the belief of having had # COVID19 than to actual SARS-Co-V2 infection. Clinicians and researchers should also consider general mechanisms that may not be specific to #SARS-CoV-2 https://t.co/IdSh5GhdQ6
– JAMA Internal Medicine (@JAMAInternalMed) November 8, 2021
The study noted an exception: the loss of smell, the only lasting symptom that would be associated with a real infection, proven by a positive serological test.
Results “which do not call into question the existence of the long Covid”
“Our results do not in any way say that the disorders reported by the patients are imaginary or psychosomatic”, explains to franceinfo Cédric Lemogne, head of the adult psychiatry service at Hôtel-Dieu, in Paris, and study coordinator. “Our analysis suggests that the presence of prolonged symptoms is not specifically associated with having been infected with Covid-19. This study does not suggest that these symptoms do not exist. If patients experience them, it is that they exist “, he insists.
According to the psychiatrist, the objective of this scientific work is above all to show that he “must remain very open on all the mechanisms that could explain the long Covid.” Through this study, Cédric Lemogne aims to prevent caregivers: “They see patients who think they have had the Covid but who have in fact experienced another viral episode.” And the study coordinator concluded: “These symptoms may be related to another illness, and you have to be careful about attributing it to a long Covid, as these are very general symptoms.”
A study criticized because it is based on serological tests
This publication is criticized, in particular because it is based on serological tests to certify exposure to the virus. “A serological test (…) is not reliable as a marker of a previous infection”, judge the British virologist Jeremy Rossman, quoted by the organization Science Media Center (in English).
“Serology is a very imperfect way of detecting whether people have had the virus, I agree. This is also discussed in the article,” admits Cédric Lemogne. But according to the psychiatrist, “the probability of having been exposed is twenty times greater in the case of a positive serology compared to a negative serology.” He also specifies that positive serological tests “have been duplicated with diagnoses, medical opinions, PCR tests or scanners”.
According to the study coordinator, having identified loss of smell as an exception symptom “is proof that the method used is capable of distinguishing which supposed manifestations of long Covid are really linked to an infection”.
Doctors fear instrumentalisation of the study
Many doctors fear an instrumentalisation of the results published in the article in Jama, “to assert that [le Covid long] is absolutely not a problem “, fears the American doctor F. Perry Wilson, professor at Yale University, on the specialized site Medscape (in English).
That’s also the case of Jérôme Larché, internist, resuscitator and referent infectious disease specialist for the independent group Oc Santé (which brings together around twenty establishments in the Occitanie region). He denounces to franceinfo a “psychologization harmful to the patient and to the dynamics that some caregivers are trying to put in place for better care” of the Covid long.
“The symptoms were confused with beliefs. The term was cited 44 times in the study, and when this term is mentioned with such recurrence in an article, it is because there is a confirmation bias, which is quite disturbing in a medical and scientific study. “
Jérôme Larché, infectious disease specialist specializing in long Covidto franceinfo
A bias also denounced by AprèsJ20, the French association of patients with long Covid. In a tweet posted on Thursday, she considers that the conclusions of the study are “stigmatizing, dangerous and harmful for long Covid (s), especially as they are contested and not recognized by the entire scientific community and international associations”.