The role of sleep quality in mediating the relationship between habenula volume and resilience

Background: Our human volumetric MRI study (Dai et al., 2024) demonstrated that habenula (Hb) volume is associated with psychological resilience, a key protective factor against depression. However, the biological mechanisms underpinning this relationship remain unclear. A recent animal study highlighted that neuronal activity in the Hb modulates rapid eye movement (REM) sleep, influencing depressive behaviors during wakefulness. Based on this, we hypothesized that sleep quality mediates the relationship between Hb volume and psychological resilience in humans.

Methods: We utilized a deep learning-based automated segmentation model to estimate Hb volume from 3T-MRI T1-weighted images of 84 healthy participants. Correlation analyses were performed to examine the relationship between Hb volume and questionnaire-based assessments of sleep quality. Mediation analysis was then conducted with Hb volume as the independent variable, psychological resilience as the dependent variable, and sleep quality as the mediator.

Results: Hb volume was found to be negatively correlated with sleep disturbance, indicating that individuals with larger Hb volumes experienced better sleep quality. A lateralization effect was also observed, where greater leftward asymmetry (larger left Hb volume compared to right) was associated with more severe sleep disturbances. Moreover, sleep quality was identified as a mediator in the relationship between Hb volume and psychological resilience.

Conclusion: This study provides preliminary evidence of the association among Hb volume, sleep quality, and resilience. Sleep quality appears to be a critical mediator in the biological processes linking smaller Hb volumes to decreased psychological resilience. Enhancing sleep quality may be a promising approach for bolstering psychological resilience and reducing the risk of depression.