Abstract
<jats:p>Introduction: Cognitive dysfunction (&quot;brain fog&quot;) is a common manifestation of post-acute COVID-19 syndrome (PACS) and may persist long after the acute infection. While cross-sectional studies have described cognitive deficits, longitudinal evidence on recov-ery trajectories remains limited. Methods: We conducted a longitudinal observational study of neurocognitive performance and neuropsychiatric symptoms in patients with PACS. Participants underwent assessment with 20 standardized tests covering five cogni-tive domains (memory, attention, language, executive functions, psychomotor processing speed); anxiety, depression, and sleep quality were assessed at three time points. Changes were analysed using the Friedman test. Results: Forty-two patients were included (median age 57 years; 35.7% female) from a predominantly hospitalized cohort (81% hospitalised; 66.7% requiring respiratory support). Comparison with non-completers (n=544) showed that completers were more severely ill during the acute phase rather than healthier or more motivated. Significant improvements over time were observed in verbal short-term learning, visuospatial memory, working memory, constructional praxis, phonological verbal fluency, and psychomotor processing speed (all p≤0.05). Sleep quality also im-proved (p&lt; 0.0001). Conclusion: Patients with PACS may show gradual, heterogeneous and domain-specific cognitive improvement, with persistent deficits in a proportion of in-dividuals. These findings highlight the importance of long-term neuropsychological mon-itoring and integrated cognitive-psychiatric evaluation in post-COVID care. Given the small, predominantly hospitalized sample, improvements should be interpreted cau-tiously and confirmed in larger controlled studies, although alternate test forms make practice effects unlikely.</jats:p>