How is psychological stress linked to sleep quality? The mediating role of functional connectivity between the sensory/somatomotor network and the cingulo-opercular control network.

How the functional connectivity of brain networks affects the relationship between psychological stress and sleep quality remains unclear. To better understand the associations between psychological stress, resting-state functional connectivity (RSFC), and sleep quality, we used the RSFC, Pittsburgh Sleep Quality Index (PSQI), and Psychosomatic Tension Relaxation Inventory (PSTRI) to investigate the relationship between psychological stress, sleep quality, and RSFC in four brain networks, the sensory/somatomotor (SM) network, cigulo-opercular control (CO) network, default mode (DM) network, and dorsal attention (DA) network, in a large healthy sample of 315 college students from Southwest University. Results showed that the brain functional connectivity in the SM, CO, DM, and DA networks was significantly correlated to sleep quality. Meanwhile, we also found that the brain functional connectivity between the SM and CO networks partially mediated the relationship between psychological stress and sleep quality, suggesting that psychological stress has an important effect on individuals' sleep quality, and increased functional connectivity between the SM and CO networks provides a neural basis for the association between psychological stress and poor sleep quality.