The purpose of this study is to investigate the differential impact of various COVID-19 stressors (economic, infection fears, grief, and lockdown stressors) and their cumulative impact on peri-post-COVID-19 syndrome. Peri-post-COVID-19 syndrome (PPCS) is a mental health and cognitive syndrome associated with chronic traumatic stress, particularly COVID-19. The sample consisted of 490 Kuwaiti citizens aged 18–60 years ( M = 24.97, SD = 9.10), with 66.3% being female. Data were collected from October 2021 to January 2022. We assessed how individuals felt about COVID-19 stressors, cumulative traumatic events and stressors, complex PTSD (CPTSD), PTSD, anxiety, depression, and executive functions. A structural equation was used to test the differential and cumulative impact of COVID-19 stressors. COVID-19 cumulative stressors, especially lockdown, had the strongest correlation with CPTSD. The highest variance was accounted for by lockdown stressors ( R2 = .752). COVID-19 cumulative stressors had a medium-to-large effect on PPCS. In the affluent Kuwaiti context, lockdown stressors appear to have a greater impact on mental health and executive dysfunction than other COVID-19 stressors. In the PPCS, CPTSD appears to be the most robust outcome variable. Conceptually, the study provided preliminary evidence of the PPCS and associated cognitive deficits as powerful drivers for COVID-19 and of continuous/prolonged traumatic stress for COVID-19. The study highlighted the need for innovation in developing multiparameter intervention strategies with a pericognitive and cognitive training component to address the multiple impacts of the pandemic.