Sleep disturbance and depressive symptoms in later-life: Cross-sectional examination of cognitive mechanisms

Background

Sleep disturbance relates to depressive symptom endorsement. The mechanisms relating these variables are not clearly elucidated, though inhibitory control and rumination are believed to play key roles. The current study aims to elucidate the relationship between sleep disturbance and depressive symptoms by examining the moderated mediating effect of inhibitory control and rumination.

Methods

The sample included 41 community-dwelling older adults (age 70 and older). Measures included the Pittsburg Sleep Quality Inventory, a stroop task (inhibitory control), the Ruminative Responses Scale, and the Geriatric Depression Scale. A series of bootstrapped models were employed to test hypotheses using a stepped approach.

Results

Worse sleep disturbance was associated with higher rumination and depressive symptoms; however, these associations were no longer significant among older adults with higher inhibitory control. The association between sleep disturbance and depression was fully attenuated by rumination, and inhibitory control significantly moderated the association between sleep disturbance and rumination in the final model.

Limitations

The smaller cross-sectional nature of the study as well as the restricted demographics of the participants (i.e., highly educated and primarily White) were the primary limitations of the study.

Conclusion

Among community-dwelling older adults, the association between sleep disturbance and depression is mediated by rumination, and this effect is mitigated by inhibitory control. As such, these findings suggest that inhibitory control may be a relevant target for intervention in older adults with poor sleep quality, rumination, and depressive symptoms.