Alterations of functional connectivity in young people with depression mediate the relationship between sleep quality and cognitive function

Sleep disturbances is common in young people with depression, and poor sleep quality affects the ability to learn. In this study, we examined possible resting-state functional connectivity abnormalities between regions of interest, and clarified the relationship with depressive symptoms, sleep quality, and cognitive function. Resting-state functional magnetic resonance imaging (fMRI) was collected on 42 healthy controls (HCs), 82 youth depressive patients (44 without sleep disturbances (NSD), and 38 with sleep disturbances (SD)). Regions of interest were defined by using Brainnetome Atlas. Functional connectivity was calculated, and its associations with depressive symptoms, sleep quality, and cognitive function were examined using correlation analysis and mediation analysis. The left and right caudal of cingulate gyrus, tongue and larynx region of postcentral gyrus were significant brain regions in NSD versus SD. The average functional connectivity between these regions was associated with poor sleep quality (r = 0.368, p = 0.001) and worse working memory (r = −0.256, p = 0.023) and mediated the relationship between sleep quality and working memory (c = −0.738, c' = −0.500). Data consistency in this study was not good enough. This study did not monitor sleep rhythms to provide objective sleep-related data. The functional connectivity between the left and right caudal of cingulate gyrus with tongue and larynx region of postcentral gyrus may be the neural mechanism by which sleep disturbances affect working memory. This provides an intervention target for clinically improving cognitive function in young people with depression.