Abstract: Objective: To analyze the development trajectory and influencing factors of Post-Traumatic Stress Disorder (PTSD) symptoms in young and middle-aged patients after first-ever stroke, providing a basis for targeted psychological interventions. Methods: This study recruited young and middle-aged first-ever stroke patients hospitalized in the Neurology Department of a tertiary grade A hospital in Shanghai from March 2022 to March 2023 by using convenience sampling method. Patient data were collected within two weeks of the stroke, included general information and scores from the PTSD screening scale. A 12-month longitudinal follow-up was conducted, and latent class growth model was used to identify PTSD trajectories, with multiple Logistic regression analysis to predict influencing factors. Results: Patients were divided into delayed progression (39.9%) and non-PTSD (62.1%) groups. The former exhibited a "high-low-high" fluctuation, while the latter showed a continuous decline. Multivariate analysis revealed moderate/severe dependence (OR=5.310), severe neurological impairment (OR=4.650), acute stress disorder (OR=2.070), and high recurrent risk perception (OR=1.062) as risk factors for delayed progression, while high psychological resilience (OR=0.907) was protective. Conclusion: Young and middle-aged first-ever stroke patients exhibit two distinct PTSD trajectories. Medical staff can promote post-traumatic growth and prevent PTSD progression by leveraging patients' psychological resources.

Key words: young and middle-aged; ischemic stroke; Post-Traumatic Stress Disorder; trajectory; longitudinal study