Functional connectivities among certain brain regions may mediate the association between sleep quality and depressive symptoms, suggests research published in JAMA Psychiatry.
Researchers recruited 1017 participants (53.7% women) from the Human Connectome Project, an existing trial with a study population generally representative of the United States. Participants were between 22 and 35 years of age, and each completed the Depression Problems scale and self-reported sleep quality. Higher depressive scale scores were correlated with poor sleep quality (P <.001). Investigators used resting-state functional magnetic resonance imaging to examine connectivities among 250 gray matter regions of interest. A network-based statistical method was used to identify significant connectivities among brain regions.
Research methods identified 162 functional connectivity links associated with sleep, among which 39 were additionally associated with the Depressive Problems score. The brain areas with a demonstrated association with sleep and depressive symptoms included the lateral orbitofrontal cortex, cingulate cortex, precuneus, angular gyrus, and temporal cortex. Notably, 92 participants (9.0%) in the study population had prior diagnoses of depression; when removed from analyses, the majority of these identified brain links remained significant, although not links involving the lateral orbitofrontal cortex. The 39 functional connectivities associated with both study metrics had a mediating effect on the relationship between sleep quality and depression (P <.001).
These data suggest a neurologic basis for the relationship between sleep quality and depressive symptoms, even among patients with no clinical diagnosis of depression. Such results could be useful in developing treatments for patients with depression or poor sleep quality.
Cheng W, Rolls ET, Ruan H, Feng J. Functional connectivities in the brain that mediate the association between depressive problems and sleep quality [published online July 25, 2018]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2018.1941