The subcortical correlates of self-reported sleep quality

Abstract

Study objectivesTo assess the association between self-reported measures of sleep quality and cortical and subcortical local morphometry. MethodsSleep quality, operationalized with the Pittsburgh Sleep Quality Index (PSQI), and neuroanatomical data from the full release of the young adult Human Connectome Project dataset were analyzed (N=1,112; 46% female; mean age: 28.8 years old). Local cortical and subcortical morphometry was measured with subject-specific segmentations resulting in voxelwise gray matter difference (i.e., voxel based morephometry) measurements for cortex and local shape measurements for subcortical regions. Associations between the total score of PSQI, two statistical groupings of its subcomponents (obtained with a principal component analysis), and their interaction with demographic (i.e., sex, age, handedness, years of education) and biometric (i.e., BMI) variables were assessed using a general linear model and a nonparametric permutation approach. ResultsSleep quality-related variance was significantly associated with subcortical morphometry, particularly in the bilateral caudate, putamen, and left pallidum, where smaller shape measures correlated with worse sleep quality. Notably, these associations were independent of demographic and biometric factors. In contrast, cortical morphometry, along with additional subcortical sites, showed no direct associations with sleep quality but demonstrated interactions with demographic and biometric variables. ConclusionsThis study reveals a specific link between self-reported sleep quality and subcortical morphometry, particularly within the striatum and pallidum, reinforcing the role of these regions in sleep regulation. These findings underscore the importance of considering subcortical morphology in sleep research and highlight potential neuromodulatory targets for sleep-related interventions. Statement of SignificanceThis study provides evidence for the role of subcortical structures in sleep regulation, demonstrating that poorer self-reported sleep quality is associated with reduced shape measures in the bilateral caudate, putamen, and left pallidum. These associations were independent of demographic and biometric factors, distinguishing subcortical morphometry as a unique correlate of sleep quality. In contrast, cortical morphology exhibited no direct relationship with sleep quality but showed interactions with factors such as sex, BMI, and age, highlighting the complexity of brain-sleep relationships. These findings contribute to a growing body of literature emphasizing the basal ganglias role in non-motor functions, including sleep regulation, and suggest potential neuromodulatory targets for sleep-related interventions, such as transcranial focused ultrasound or deep brain stimulation.