Depression is one of the common psychiatric diseases worldwide. Previous studies showed that chronic stress could increase defecation and inhibit weight gain; however, the effects of chronic stress on gastrointestinal peristalsis had not been clarified. To study the mechanisms of depression, chronic restraint stress (CRS) is widely used as a traditional depressive animal model. In this study, we investigate the effects of CRS on gastric emptying and intestinal propulsion in mice. Our results showed that the mice exhibited obvious depression-like behaviors 4 weeks after CRS. Compared with the control group, gastric emptying and intestinal propulsion were significantly decreased in the CRS group. Further, we examined the expression of ArhGEF18, a Rho-specific guanine nucleotide exchanging factor, which was significantly reduced in the gut in the CRS group. Therefore, CRS caused depressive behaviors and abnormal gastrointestinal function. The ArhGEF18-RhoA/Rho signaling pathway may be a potential mediator in the brain–gut axis under stress.

On January 30, 2020, the World Health Organization (WHO) announced COVID-19 as the sixth public health emergency of international concern, and on March 11, 2020, the WHO declared that COVID-19 is a pandemic. To date, patients with COVID-19 are present in most countries in the world. Coronavirus disease 2019 (COVID-19) is caused by a coronavirus SARS-CoV-2. The COVID-19 virus and the 2003 severe acute respiratory syndrome (SARS) virus are approximately about 79% homologous, and their transmission modes are similar, but the transmission speed and range of COVID-19 virus far exceed those of the 2003 SARS virus, causing people to experience panic, anxiety, and depression. After the SARS epidemic, many survivors and medical workers had severe post-traumatic stress disorder (PTSD), which seriously affected their quality of life. Here, we reviewed the situations of PTSD after the SARS epidemic. The lessons and experiences of PTSD caused by SARS may help deal with the more severe occurrence of PTSD during and after the COVID-19 epidemic.