This study conducted a cognitive function screening for elderly adults living in pension institutions, and adopted the highly valid and reliable GDS as the main assessment tool for evaluating depression and its influencing factors among elderly adults without cognitive dysfunction. The findings of this study can be characterized as a good representation of the population (and thus bearing high information reliability). The conclusions drawn also have strong generalizability. The results of this study showed that the depression rate among elderly adults without cognitive dysfunction living in pension institutions in Northeastern China was 21.7%, which is much lower than that in Beijing 13 (n = 107, 32.71%) and Guangdong Province 14 (n = 379, 38.5%). The depression rate among elderly adults with poor sleep quality was 31.1%, which was significantly higher than that among elderly adults with good sleep quality (12.3%). The results were similar to those pertaining to elderly adults living in pension institutions in Beijing13.
Elderly adults showed significant differences in depression, marital status, economic status, chronic disease, self-care, chewing ability, ability to go out alone, regular exercise, regular diet, filial piety, and loneliness according to sleep quality. Similarly, Dai and Li et al. 5,13 found a significant negative correlation between sleep quality and depression. Poor sleep quality in elderly adults can trigger feelings of irritability, listlessness, fatigue, weakness, and even deepen their negative experiences of the aging process, thereby leading to the emergence of depression. Moreover, the interactions between sleep quality and other factors influencing depression had significant effects on elderly depression. These findings further indicated that the factors influencing depression in elderly adults differ according to sleep quality. Therefore, the risk factors of depression in elderly adults with good and poor sleep quality were analyzed separately, enabling us to propose specific recommendations to reduce the incidence of depression among elderly adults and thereby improve their quality of life.
Marital status is an important risk factor for depression among elderly adults with good sleep quality. Spousal support and care can reduce the incidence of depression: indeed, the incidence of depression in widowed elderly adults was significantly higher than that among married elderly adults15. Divorced elderly adults or those in poor marriages are also more likely to suffer from mental health problems and increased depression16. The elderly population is a high-risk group in terms of the incidence of various chronic diseases, which harm the physical and mental health of elderly adults and impact their normal lives and social communication, thus triggering depression 17. Regular exercise can strengthen the body and increase the opportunity to communicate with others while exercising, thereby sustaining feelings of pleasure among elderly adults 18. Appropriate exercise can also promote elderly adults’ sleep quality. Therefore, elderly adults living in pension institutions should be encouraged to exercise more. In this study, elderly adults who often experienced body aches had a higher risk of depression. Body aches are likely to increase discomfort among elderly adults, which in turn can affect their daily activities and increase their negative emotions. Furthermore, children’s filial piety can increase feelings of comfort and warmth among elderly adults, which can greatly reduce the occurrence of depression 19. Therefore, elderly adults in pension institutions would require more attention from their children. In addition, chewing ability was found to have an impact on depression among participants. Good chewing ability can ensure adequate intake of nutrition, thus ensuring that elderly adults can enjoy good health and a pleasant mood.
For elderly adults with poor sleep quality, loneliness is an important risk factor of depression. Insomnia can increase elderly adults’ sense of loneliness, which is likely to cause depression 13. As for self-care, researchers have found that self-care ability can sufficiently reflect elderly adults’ basic degree of self-care as well as their general health status. Additionally, one study 20 showed that depression and self-care ability have a mutual causal relationship, such that a decline in self-care ability will lead to the aggravation of depression. Similarly, chewing ability and chronic diseases also have an impact on depression among elderly adults with poor sleep quality. Therefore, we should pay close attention to the chewing ability and physical health of elderly adults. Pension institutions should make soft food available to elderly adults (depending on their chewing ability. These institutions should also conduct regular physical examinations of elderly adults, supervise the rational and timely use of drugs among elderly adults with chronic diseases, and formulate measures to reduce disease-related psychological burdens for elderly adults, thereby reducing the incidence of depression among elderly adults living in pension institutions.
There were some limitations in our study. First, measures for some of the factors, such as smoking and chewing ability, were simplistic and broad, and therefore could have weakened our assessments of their effects. Second, although the present study was a population-based study on depression among elderly adults with different sleep quality in pension institutions in Northeastern China, it was limited by its cross-sectional design. Therefore, all conclusions drawn from this study should be confirmed in a future prospective study.
In conclusion, this study is the first to assess depression among elderly adults with different sleep quality in pension institutions in Northeastern China and to clarify its associated factors. Our results revealed that the prevalence of depression differed among elderly adults according to their sleep quality. Marital status, chronic disease, regular exercise, body aches, filial piety, and chewing ability had considerable effects on depression among elderly adults with good sleep quality. By contrast, loneliness, self-care, chewing ability, and chronic disease had considerable effects on depression among elderly adults with poor sleep quality. Our findings suggest that there should be a focus on the maintenance of health status and psychological factors to reduce the incidence of depression among elderly adults in pension institutions.