Background: This study explores the longitudinal psychosocial impact of Long-COVID syndrome, also known as Post-COVID-19 syndrome, characterized by enduring symptoms after coronavirus disease (COVID-19) infection, over the years 2020, 2021, and 2022. It aimed to examine the variations in depression, anxiety, and quality of life among Post-COVID-19 patients during these years, hypothesizing significant inter-year differences reflecting the pandemic's evolving influence.

Methods: Conducted at Victor Babes Hospital for Infectious Diseases and Pulmonology, Romania, this cross-sectional research involved 324 patients diagnosed with mild to moderate COVID-19, assessed six months post-hospitalization. Standardized instruments, namely Short Form (SF-36) for quality of life, Generalised Anxiety Disorder Assessment (GAD-7) for anxiety, and Patient Health Questionnaire (PHQ-9) for depression, were utilized.

Results: The study observed a consistent average patient age of around 55 years across the years. A notable increase in COVID-19 vaccination rates was recorded, rising from 20.9% in 2020 to over 70% in 2022 (p<0.001). Trends in key post-COVID symptoms like fatigue and cognitive issues varied over the years. Importantly, there was a consistent decrease in feelings of sadness or depression, with scores declining from 7.3 in 2020 to 4.8 in 2022 (p<0.001). The SF-36 survey indicated a steady improvement in overall health, reaching 55.8±7.1 in 2022 (p=0.035). Both GAD-7 and PHQ-9 scores showed significant reductions in anxiety and depression over the years, with p-values of 0.030 and 0.031, respectively. Factors such as smoking status, substance use, and the initial severity of COVID-19 infection were significantly associated with depression levels.

Conclusion: The findings suggest that despite persistent physical symptoms, Long-COVID patients experienced enhancements in mental well-being and quality of life over the studied period. The increasing vaccination rates might have contributed to this improvement. Addressing modifiable risk factors like smoking and substance use could further optimize post-COVID care and mental health outcomes.