Background: This study investigated the longitudinal association between psychological distress in the post-acute phase and the subsequent prolonged post-acute sequelae of COVID-19 (PASC) among individuals with PASC. Methods: An online longitudinal survey with 1-year interval was conducted from July to September 2021 (T1) and July to September 2022 (T2). Individuals who were 20-years-old or older, had a positive Polymerase Chain Reaction test, were one month post-infection, and did not select 'Nothing' to a question regarding PASC presence were included. The primary outcome was the presence of PASC at T2. The presence of general, respiratory, muscular, neurological, gastrointestinal, dermatological, and cardiac symptoms at T2 was also used as an outcome among patients with relevant symptoms at time 1 (T1). Exposure was measured using the Kessler distress scale (K6) at T1, and those whose K6 was 13 or higher were identified as having psychological distress. Marginal structure models with robust standard errors were used to examine the association between psychological distress at T1 and any PASC symptoms at T2, and the associations between psychological distress and each symptom at T2 among participants with relevant symptoms at T1. Results: A total of 1674 patients were analyzed; 17% had psychological distress. ; In total, 818 (48.9%), 523 (31.2%), and 672 (40.1%) patients reported general, respiratory, and neurological symptoms at T1, respectively. Individuals with psychological distress had higher odds of any symptoms at T2 (Odds Ratio [OR] =1.81, 95% Confidence Interval [CI]= 1.08 - 3.03) and general and respiratory symptoms at T2 among participants with relevant symptoms at T1 (OR = 1.95, 95% CI = 1.02 - 3.76; OR = 2.44, 95% CI = 1.03 - 5.80). Conclusion: Psychological distress in the post-acute phase may lead to prolonged PASC symptoms, mainly general and respiratory symptoms, at the 1-year follow-up in individuals with PASC.

DN reports personal fees from Startia, Inc., en-Power, Inc., MD.net, and Takeda Pharmaceutical Company, Ltd. outside of the submitted work. MH, MK, ZN, EO, and KU have no financial conflicts of interest to disclose concerning the study.

This work was supported by an Intramural Research Grant for Neurological and Psychiatric Disorders of the National Center of Neurology and Psychiatry (grant number 1-6 and 4-3).

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