Is recovery just the beginning? Persistent symptoms and health and performance deterioration in post-COVID-19, non-hospitalized university students-a cross-sectional study

Abstract

Many individuals experience persistent symptoms such as deteriorated physical and mental health, increased fatigue, and reduced cognitive performance months after recovering from coronavirus disease 2019 (COVID-19). There is limited data on the long-term trajectory and prevalence of these symptoms, especially in milder cases. Our study aimed to assess the persistent effects of COVID-19 on physical and mental health, fatigue, and cognitive performance in a cohort of 214 students, averaging 21.8 years of age. Of these, 148 had contracted COVID-19 but were not hospitalized, with the time since infection ranging from 1 to 39 months. We utilized a comprehensive panel of cognitive tests to measure intelligence, memory, and psychomotor skills, and a detailed anamnestic questionnaire to evaluate physical and mental health. While contracting COVID-19 did not significantly impact overall health and performance, it was associated with increased reports of fatigue. However, the reported severity of the disease had a pronounced negative influence on physical health, mental well-being, fatigue, and reaction time. Trends of improvement in physical and mental health, as well as error rate, were observed within the first 2 years post-infection. However, fatigue and reaction time showed a trend of deterioration. Beyond the 2-year mark, physical health and error rate continued to improve, while mental health began to deteriorate. Fatigue and reaction time continued to decline. Overall, our findings suggest that some effects of contracting COVID-19 can persist or even deteriorate over time, even in younger individuals who had mild cases that did not require hospitalization.

Keywords: COVID-19; SARS-CoV-2; cognitive performance; fatigue; long COVID; long-term effects; mental health; physical health; post-COVID sequelae.

Figure 1.

Distribution of age of participants and times since the beginning of COVID-19.

Figure 2.

Effects of severity of COVID-19 (course) on five health and performance-related indices. The figure displays boxplots representing the distribution of five health and performance-related indices across various categories of COVID-19 severity for both men and women. Each box encompasses the interquartile range (IQR), with a line inside the box indicating the median. The whiskers extend beyond the box to illustrate the range of variability (95% Confidence Intervals [CIs]), and black squares denote the mean scores for each index.

Figure 3.

The correlation between the time since COVID-19 and five health and performance-related indices. This scatterplot illustrates the relationships between five health- and performance-related variables and the time elapsed since contracting COVID-19. To visualize the trends, the points for each variable are fitted by polynomial curves, chosen based on comparisons of Adjusted R-Squared values. Specifically, a second-degree polynomial curve is fitted for Physical Health, a fourth-degree polynomial curve for Mental Health, a second-degree polynomial curve for Fatigue, a first-degree polynomial curve for Error Rate, and a first-degree polynomial curve for Reaction Times. (For the figure where data for all variables were fitted with the third-degree polynomial curve, see Supplementary Fig. S1). Higher values on the y-axis indicate worse health and performance. The bands around the lines represent 80% CIs.