Fig. 1.

Workflow and framework of this study. Panel A illustrates the screening procedures of eligible participants for this study. The left bar denotes the timeline of the data acquisition in this study, with the “data acquisition” referring to the time duration of brain scanning, “begins” referring to the date of the beginning of the COVID-19 epidemic in mainland China, “recruit” for the beginning date of the follow-up data acquisition, and “ends” for the end date of follow-up data acquisition. The red bar refers to the timeline before the onset of the COVID-19 epidemic in mainland China, whilst the blue bar refers to the timeline after the onset of the COVID-19 epidemic in mainland China. Dots alongside of the timeline show the corresponding date of scanning (Top) and follow-up tests (Bottom) for PTSD+ (dark pink) and PTSD- (light pink). Panel B describes the support vector machine model (SVM) for the pseudo-prospective cohort design. The features of this model are the neural connectome of the PTSD network and the performance of the SVM that are obtained in leave-one-subject-out cross-validation (LOSOCV). Panel C depicts the model of ensemble learning by using Baggoing sampling. Panel D refers to the predictive framework of the pseudo-prospective cohort design. Discriminative features identified in the classification model were used as a feature for prediction of PTSD symptoms in the PTSD+. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)