Neural Mechanisms Underlying the Impact of Psychological Resilience on Psychosocial Stress Responses.

High psychological resilience (HR) could protect individuals from psychosocial stress and thereby make individuals less vulnerable to depression and anxiety; however, the underlying neural mechanism remains to be investigated. The Montreal Imaging Stress Task (MIST) was administered to participants of 59 healthy individuals with HR and 56 individuals with low psychological resilience (LR) during functional magnetic resonance imaging (fMRI) scanning. Cortisol concentrations and subjective stress levels were collected across the MIST. Repeated measures analyses of variance were conducted to measure the group differences in subjective and cortisol stress responses. Two-sample -tests were conducted to detect the group differences in stress-related brain activation and functional connectivity (FC). The LR group exhibited an increase in cortisol concentration after the MIST, whereas the HR group exhibited a decrease in cortisol concentration after the MIST. The LR group exhibited higher activation in the left anterior insula and lower FC between the left orbitofrontal cortex (OFC) and the right temporal pole (TP) (all  < 0.05). Mediation analyses revealed that the left anterior insula mediates the relationship between psychological resilience and depression and the left OFC-right TP FC mediates the relationship between psychological resilience and anxiety. Findings highlight that the anterior insula and OFC-TP FC could be the critical neural mechanism underlying the interaction between psychological resilience and psychosocial stress. Moreover, higher anterior insula activation and lower OFC-TP FC could be the crucial neural mechanism of individuals with low psychological resilience developing into depression/anxiety when experiencing daily psychosocial stressors.