Analysis of the temporal dimension of the relationship between psychological factors and post-COVID-19 conditions (PCC)

Most people who had COVID-19 have fully recovered, but research shows that about 10-20% of individuals experience lingering symptoms that persist for weeks or even months after being infected, a condition commonly known as long COVID. In July 2021, the Public Health Agency of Canada acknowledged long COVID as a significant public health issue. By August 2022, over 1.4 million Canadians - about 15% of adults who had COVID-19 - reported experiencing symptoms lasting three months or more after their initial infection. With such a large number of people affected, the impact of these long-term symptoms on individuals, families, the healthcare system, and the economy could be substantial. Long COVID remains a poorly understood condition, with no clear cause, prevention, or treatment options available, and with a growing list of over 200 symptoms, affecting multiple organs and leading to mental health challenges. This raises the hypothesis of a possible psychological component associated with this condition. The main goal of this doctoral thesis is to explore the link between psychological factors and long COVID. Two studies will be carried out to explore this relationship. The first study will be a systematic literature review, summarizing existing research to determine whether mental health issues and psychological stress are more likely to occur before or after the onset of post-COVID-19 symptoms. The second study will examine the timing of this association in a large, longitudinal population sample, aiming to understand how psychological factors and long COVID are connected over time. This project will determine whether there is strong evidence of a relationship between psychological factors, including stress and mental health disorders, and long COVID. Understanding whether psychological distress or stress leads to long-term COVID-19 symptoms, or if the symptoms cause distress, will help us better understand the development of long COVID, and could improve treatment.