Background: Although sleep problems are associated with a wide range of mental problems, it remains uncertain whether the global Pittsburgh Sleep Quality Index (PSQI) score is related to depressive symptoms in an adult population.
Patients and Methods: Data from the Midlife in the United States (MIDUS) study, including a general adult population, were obtained. A total of 1002 individuals (aged 34– 84 years) were included in this study. Linear regression and logistic regression analyses were performed to investigate the association between sleep parameters from the PSQI score and depressive symptoms.
Results: The median age of all participants was 53.0 years old, and 45.2% of them were male. After adjustments were made for sociodemographic characteristics, lifestyle factors, currently diagnosed diseases and inflammatory markers, global PSQI score was significantly associated with depression score in the linear regression model (0.298 [0.207– 0.389], P < 0.001; Model 3). A higher global PSQI score was independently and significantly associated with depressive symptoms (score ≥ 16) in the logistic regression model (1.235 [1.150– 1.325], P < 0.001; Model 3). Stratified analysis showed that the independent association between global PSQI score and depressive symptoms was affected by hypnotics use, but not antidepressants use.
Conclusions: A higher global PSQI score is significantly associated with a higher risk of depressive symptoms in an adult population from the United States. Future longitudinal and interventional studies are warranted to assess whether reducing the global PSQI score may improve symptoms of depression.
Keywords: Pittsburgh Sleep Quality Index, depression, cross-sectional study