In this study, all FES patients were recruited from the First Affiliated Hospital of Shenzhen University between March 2008 and November 2018. Consensus diagnosis of FES was reached based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis criterion (43). Exclusion criteria included history of substance dependence, other diseases of the central nervous system, or unstable medical conditions. In order to eliminate the confounding effect of neuroleptic medication, all FES patients were antipsychotic-naïve. Meanwhile, we recruited age and gender matched healthy controls (HCs). All participants volunteered to be part of this research and had the right to withdraw at any time. Informed consents were obtained from all participants or family relatives, as approved by the Ethics Committee at the First Affiliated Hospital of Shenzhen University.

The demographic information of all participants is shown in Table 1. A total of 198 participants were involved, including 92 FES patients (50 females and 42 males) and 106 HC participants (47 females and 59 males), aged from 12 to 43 years (FES patients' average age = 22.40 ± 5.59 years; HC participants' average age = 23.68 ± 4.04 years). There is no significant group difference on either sex (P = 0.16) or age (P = 0.071) or duration of education (P = 0.43). The Global Assessment of Function (GAF) (44) and the Positive and Negative Syndrome Scale (PANSS) (45) were used to, respectively, assess the severity of FES patients in terms of social function and clinical symptoms.

Demographic information.