Chronic Fatigue Syndrome & Long COVID: Similarities and Differences

March 29, 2023

Over 60% of patients who experience a COVID-19 infection report physical and mental fatigue and what they refer to as “brain fog.” These symptoms are often grouped as a post‑COVID‑19 condition or long COVID. Patients suffering from Myalgic Encephalomyelitis (ME), commonly known as Chronic Fatigue Syndrome (CFS), are also affected by similar symptoms, and people affected by both conditions suffer from “slow processing speed, deficient sustained attention, and verbal memory impairment” (1). 

Researchers asked whether these two conditions are the same, with the only difference being the initial trigger. 

Levels of depressive symptoms, fatigue, sleep quality, anxiety, as well as olfactory and cognitive functions were evaluated amongst 42 ME/ CFS patients and 73 long COVID patients. Based on the available data, researchers concluded that even though ME/ CFS patients’ symptoms were more severe, there were similarities between patients in both groups. ME/ CFS and long COVID patients suffered from “high levels of fatigue, poor sleep quality, anxiety, and depressive symptoms.” However, ME/ CFS patients suffered more frequently from “dizziness, instability, high-temperature sensation, and muscle weakness.” Patients with ME/ CFS also performed worse in attention and visual perception tasks. 

Researchers observed that the cognitive performance of long COVID patients correlated with physical ailments and mood disturbances, while for ME/ CFS patients, cognitive performance correlated with anxiety symptoms and physical fatigue. 

The authors of this study mention the importance of treating anxiety and depressive symptoms in patients with both conditions as they can have ties to suicidal thoughts. They also point to some limitations in the study; for example, the lack of a control group (including healthy participants who do not have a history of COVID-19 infection and don’t suffer from ME/ CFS). Additionally, most of the study’s participants were Caucasian and unvaccinated, making it difficult to draw conclusions about vaccinated patients who experienced COVID-19 infection or people of different races.