Perceived sleep quality is associated with depression in a Korean elderly population.

Our study aimed to examine the relationship between perceived sleep quality and depression using Pittsburgh Sleep Quality Index (PSQI) and Cole's model to materialize the concept of perceived sleep quality in the non-cognitively impaired elderly. Older adults aged 60+ were recruited from the baseline study of Suwon Project (SP) between 2009 and 2011 (n=2040). Perceived sleep quality was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI-K), and depression was accessed using the Korean version of the Geriatric Depression Scale-Short Form (SGDS-K). We excluded the cognitively impaired elderly using the Korean version-Mini Mental Status Examination (K-MMSE) score less than or equal to 17. In multivariable adjusted logistic regression related to PSQI-K components, poor perceived sleep quality, including poor subjective sleep quality (Odds ratio (OR)=1.27, 95% confidence interval (CI)=1.01-1.61), longer sleep latency (OR=1.32, 95% CI=1.13-1.55) and the frequent use of sleeping medication (OR=1.30, 95% CI=1.10-1.53) were significantly associated with depression after adjusting for age, sex, education, living status, current smoking and current alcohol drinking, the number of comorbidity and Beck Anxiety Inventory (BAI). PSQI-K global score also had greater odds of reporting depression (OR=1.12, 95% CI=1.07-1.16). These results suggested that poor perceived sleep quality was associated with a greater level of depression in the elderly.