The most common symptoms of the post-COVID-19 illness known as long lust include fatigue, shortness of breath and cognitive dysfunction, according to the World Health Organization (WHO). To be considered long COVID symptoms, they must be present for at least two months during the three months after the onset of illness.
A recent study in Brain and behavior showed that the disease had a widespread impact on attention abilities, executive functions, learning and long-term memory. Furthermore, the scientific literature estimates that between 9% and 49% of patients experience fatigue four weeks after the onset of symptoms, and this can even persist for a year in at least a third of patients.
Nevertheless, a possible link between fatigue and anxiety or depression in patients with long covid had not been studied in the laboratory. Today, a study by the Universitat Oberta de Catalunya (UOC), which has been published in open access in the Journal of Neurologyhas now shown that fatigue in long-term patients is linked to anxiety, depression and apathy.
Persistent fatigue is very debilitating and greatly limits people’s quality of life. If someone is experiencing fatigue as a result of COVID-19, it is important to investigate this situation further and determine what other symptoms or disorders are associated with this condition.”
Marco Calabria, principal investigator of the article, member of the Cognitive NeuroLab group at UOC and member of the Faculty of Health Sciences
According to the author, now that we know the link between fatigue and depression, “clinicians should explore these aspects to provide guidance for treatment recommendations”. However, something this research hasn’t clarified is the direction of the effect: “it’s not clear whether fatigue leads to depression or vice versa,” he explained.
Scientists studied a sample of 136 COVID-19 patients who suffered from cognitive deficits eight months after contracting the virus. “We found that fatigue is linked to sustained attention, which allows us to perform a task for a long time and keeps us focused, and to executive functions, which allow us to temporarily store information in order to perform tasks. tasks such as calculating, or reproducing a phrase we heard,” Calabria said.
Studying fatigue: a clinical challenge
Fatigue is characterized by excessive fatigue and physical and/or cognitive and muscular weakness. It has been associated with medical conditions such as post-viral infection and neurological diseases. Nevertheless, although it can be broadly described in these terms, there is no universally accepted definition of this clinical condition and knowledge of its underlying pathogenic mechanism is limited, which is why it represents a clinical challenge for experts.
Another challenge for scientists was to separate post-COVID-19 fatigue from the consequences of the particular situation experienced during the pandemic. “Fatigue is a symptom linked to viral infections, and this suggests that it would be one of the possible symptoms of SARS-CoV-2 infection,” said Calabria, who believes it is possible that, in early waves of the pandemic, isolation may have contributed to the increase in some symptoms. “But some observations tell us that this is not always the case: fatigue prevents many people from resuming their previous lifestyle, while others continue to suffer from fatigue although they may return to pre-existing conditions. -pandemics and we found that the prevalence of apathy associated with COVID-19 increased from 17% before infection to 62% after infection.”
According to its authors, the study findings underscore the importance of a holistic approach when evaluating and reviewing a potential treatment for COVID-19 patients with fatigue. However, there are still many unanswered questions: “how these changes are reflected at the brain level, how long they last, who is most likely to suffer from these symptoms for a long time and what are the individual characteristics that predict healing. We’ll answer all of these questions in the long term, because this field is something new and unknown,” the researcher concludes.
Open University of Catalonia
Calabria, M., et al. (2022) Post-COVID-19 fatigue: the contribution of cognitive and neuropsychiatric symptoms. Journal of Neurology. doi.org/10.1007/s00415-022-11141-8.