This study investigated the cross-sectional and longitudinal associations of physical health and lifestyle-related factors with the subjective wellbeing of older Chinese adults. Meanwhile, the study identified potential risk factors related to life satisfaction among Chinese community-dwelling older adults while considering their transitions in mental health.
In addition to the cross-sectional relationship previously documented in the literature (Olawa et al., 2020), these findings enrich the literature by indicating a longitudinal association between multimorbidity and higher depression risk among older adults, even after adjusting for demographic and health-related confounders. This result implies that poor physical health can elevate the risk of mental health problems among older adults. Meanwhile, we further found that multimorbidity was significantly related to baseline life satisfaction. This finding is consistent with prior studies indicating that chronic illness in older adults is related to lower life satisfaction (Gana et al., 2013; Phulkerd et al., 2021). It is plausible that the presence of two or more chronic diseases may increase the risk of disability or limit the capacity of individuals to participate in social activities, which may reduce subjective well-being among older adults. Available evidence synthesized by a prior systematic review has shown that compared to those without multimorbidity, individuals with comorbid physical health conditions are at twice the risk of depressive symptoms (Read et al., 2017). Those findings supported our hypotheses that multimorbidity has short-term and long-term effects on late-life subjective wellbeing.
However, we found that shorter sleep duration showed only a cross-sectional association and not a longitudinal association with a high degree of late-life depression risk, which is inconsistent with previous two-year (H. Liu et al., 2021) and four-year (Sun et al., 2018) follow-up studies among older Chinese populations. This could be partially attributed to the differential methodology between the current and prior studies, including the differences in the length of observational periods, the waves of data, and the measurement tools of late-life depression. Future research is warranted to understand the potential long-term impacts of sleep duration on the course of late-life depression.
Furthermore, our findings revealed a cross-sectional association between alcohol use and more depressive symptoms, but the relationship was not observed in the longitudinal analysis. These findings were consistent with existing cross-sectional studies indicating that alcohol consumption was a risk factor for depression in older adults (Satre et al., 2011; van den Berg et al., 2014). However, similar to the findings of a two-year follow-up study in the Netherlands (Bruin et al., 2018) and a seven-year cohort study in Japan (Tanaka et al., 2011), alcohol intake did not predict the risk of the future development of depression in this study. One possible explanation for these differing results may be the various confounder-controlling approaches incorporated into the analyses measuring the fixed and time-varying effects among previous observational and epidemiological studies (Keyes et al., 2019). Based upon the life-course model of alcohol consumption (O'Neill et al., 2017), an alternative explanation pertains to the dynamic pattern of drinking behaviors in older age and the degree of time variation in alcohol intake. As such, alcohol intake may affect the mental health status of older adults in a diverse way over time, especially when they experience life events such as remarriage, widowhood, and retirement (Keyes et al., 2019). Future studies using multiple waves of data are needed to examine longitudinal patterns of the association between changes in alcohol consumption and the development of late-life depression.
The main contribution of this study is the identification of the lifestyle-related factors contributing to life satisfaction in older adults by the categories of long-term mental health conditions, including those with no risk of clinical depression, intermittent depression, and chronic depression. The findings showed that in the overall sample, current drinkers were more likely to report lower overall life satisfaction than nondrinkers. Notably, compared to nonsmokers, older adults who quit smoking experienced a decline in life satisfaction, particularly among those with chronic depression, during the seven-year follow-up. These results resonated with previous evidence indicating a lower degree of life satisfaction with a stronger dependence on cigarettes (Dong et al., 2020; Kolosnitsyna et al., 2017). This may be explained by the poor health caused by unhealthy lifestyle behaviors (e.g., smoking) and long-term mental disorders reducing the subjective well-being of older adults. Although people have quit smoking, they may consider their health worse than nonsmokers if they accept the idea that smoking is harmful to their health (Abuladze et al., 2017; C. Li & Khan, 2022). Such findings provide a basis for further modeling analysis in future studies to explore the underlying mechanism of the reciprocal relationships among lifestyle-related factors, life satisfaction, and the developmental process of depression risk in community-dwelling older adults.
In line with previous research (Mandolikar et al., 2017; Meher et al., 2022), the current evidence indicates that female older adults are more vulnerable to depressive symptoms than their male counterparts, which could be attributed to biological factors such as sex hormones leading to sex differences in terms of the onset and severity of depression (Meher et al., 2022). Alternatively, it is possibly due to the increasing life expectancy and higher rates of widowhood among older Chinese women (D. Li et al., 2014; Q. Liu et al., 2018). Moreover, as evidence has shown the protective role of public pensions in the mental health of older adults (e.g., Chen et al., 2019; Fernández-Niño et al., 2018), our findings further revealed that older adults tended to have higher levels of depressive symptoms among those self-rating their financial status as ‘poor/relatively poor’ or not receiving a public pension, which can be explained by the insecurity and economic dependence of older people when they lack income (Li et al., 2016). This finding underpins the role of protective social welfare policies in alleviating the risk of late-life depression. In addition, the cross-sectional and longitudinal relationships between people’s education level and their depressive symptoms have been validated, which resonates with previous studies suggesting that educational level serves as a protective factor against the negative influences of depressive symptoms in older adults (Cano-López et al., 2021; Y. Li & Zhao, 2021; Q. Liu et al., 2018).
Implications
Our findings highlight the significance of advocating healthy lifestyles in preventing depression and promoting psychological wellbeing in older adults, with factors such as reducing alcohol consumption (Yawson et al., 2013), reducing dependence on cigarettes (Mattei et al., 2018), and having a longer duration of sleep (Zhi et al., 2016). Practically, our findings indicate the differential implications of modifiable lifestyle-related factors on psychosocial interventions targeted at alleviating depressive symptoms and promoting life satisfaction in older Chinese adults. Our findings also implied that psychosocial intervention should be tailored for serving older adults based on their long-term mental and physical health conditions. For instance, attention should be particularly directed towards older adults who emerge or remain at risk of depression after several years and those who have multiple chronic diseases. In addition, it is important for social workers and clinical practitioners to be sensitive to the demographic characteristics of older adults, which would help identify those who are more vulnerable and predisposed toward depression, such as female older adults, as identified in this study. Practitioners should therefore provide appropriate referrals to individuals at risk and become familiar with the mental health-related resources available in the local communities. Equally important is the development of multidisciplinary strategies that involve public health professionals, clinical practitioners, social workers, and policy-makers. Specifically, steps could be taken toward advocating healthy lifestyles in late life for the public and promoting policies on the early prevention of late-life depression.
Limitations
Several limitations should be noted. First, the self-administered survey design in this study is subject to self-report bias due to recall delays and social desirability effects. Second, this study was limited by available data on assessing life satisfaction; therefore, life satisfaction as a whole was determined by the score of a single item. Future research should use more standardized measurements of life satisfaction that could involve more subdimensions. Third, the present study did not address other lifestyle-related indicators, such as an unhealthy diet. Therefore, future research may take more factors related to an unhealthy lifestyle into account to have a more comprehensive understanding of the impacts of chronic diseases and unhealthy lifestyle behaviors on the subjective wellbeing of older adults. Fourth, given that the participants in this study were all married or living with a partner at baseline, the generalizability of our findings may be limited and therefore may not be applicable to other late-life populations with different marital statuses. Although the present study was a longitudinal study without an experimental design, the findings cannot support the inference of a causal relationship between lifestyle-related factors and physical and psychological wellbeing. Building on the preliminary results of this study, future investigations could further assess the potential reciprocal relationships among these variables.