Cheng W, et al. - As depression is associated with poor sleep quality, researchers assessed which brain areas mediate the link between depressive symptoms and poor sleep quality to further understanding of the differences in brain connectivity in depression. On analyzing 1,017 participants in the Human Connectome Project, the lateral orbitofrontal cortex, dorsolateral prefrontal cortex, anterior and posterior cingulate cortices, insula, parahippocampal gyrus, hippocampus, amygdala, temporal cortex, and precuneus all have increased functional connectivity correlated with both sleep and Depressive Problems scores. These findings may have implications for better-directed treatments for depression and associated sleep problems.

Methods

• Data from participants in the Human Connectome Project were collected using the Adult Self-report of Depressive Problems portion of the Achenbach Adult Self-Report for Ages 18-59, a survey of self-reported sleep quality, and resting-state functional magnetic resonance imaging.
• In 8,718 participants from the UK Biobank, researchers performed cross-validation of the sleep findings.
• They assessed correlations between functional connectivity, scores on the Adult Self-Report of Depressive Problems, and sleep quality as main outcomes.

Results

• From the Human Connectome Project, researchers included a total of 1,017 participants (of whom 546 [53.7%] were female; age range, 22 to 35 years) drawn from a general population in the US.
• A positive correlation was noted between the Depressive Problems score and poor sleep quality (r = 0.371; P < .001).
• They identified a total of 162 functional connectivity links involving areas associated with sleep, such as the precuneus, anterior cingulate cortex, and the lateral orbitofrontal cortex; 39 of these links were noted to be associated with the Depressive Problems scores, as well.
• The lateral orbitofrontal cortex, dorsolateral prefrontal cortex, anterior and posterior cingulate cortices, insula, parahippocampal gyrus, hippocampus, amygdala, temporal cortex, and precuneus were the brain areas with increased functional connectivity associated with both sleep and Depressive Problems scores.
• These functional connectivities were identified to underlie the association of the Depressive Problems score with poor sleep quality in the mediation analysis (β = 0.0139; P < .001).