Association between depression and sleep quality in Iranian older adults

Objective. To determine the association between depression and quality of sleep in older people in Qazvin, Iran. Methods. Older people aged ≥ 60 years who were referred to urban health centres in Qazvin, Iran between 2018 and 2019 were randomly selected via multistage cluster sampling. Inclusion criteria were ability to communicate and no history of cognitive, psychiatric, or neurological disorders (according to medical records). Depression and sleep quality of participants were assessed by two trained nurses. Depression was assessed using the validated Iranian version of the 15-item Geriatric Depression Scale (GDS-15). Sleep quality and its problems over a 1-month period was measured using the self-report Pittsburgh Sleep Quality Index (PSQI). A cut-off score of >5 is considered poor sleep quality. Results. 194 men and 206 women aged 60 to 87 years were recruited. The mean GDS score was 7.04; 255 (63.8%) had no depression and 145 (36.3%) had depression. The two groups differed significantly in terms of education (p=0.021), chronic disease (p=0.015), and economic status (p=0.026). 80% of participants had poor sleep quality (PSQI score of >5). The mean PSQI score was higher in those with depression than in those without depression (7.82 vs 6.71, P<0.001). Participants with depression also had higher subscores in sleep latency (p=0.021), sleep disturbances (p=0.047), use of sleeping medication (p=0.011), and daytime dysfunction (p=0.003). In the logistic regression analysis, poor sleep quality (PSQI score of >5) was associated with 2.55-fold increased risk of depression after adjusting for age, sex, disease, and economic status. Discussion. The prevalence of poor sleep quality and depression in Iranian older people is high. Poor sleep quality is associated with depression in older people. Interventions should be provided to improve sleep quality of older people. Measures to attract social participation, promote health status, and provide consulting services for older people are warranted.