ORIGINAL ARTICLE
The Association Between Social Capital and Depression Among Chinese Older Adults Living in Public Housing Tat Leong Wu, BSS,* Brian J. Hall, PhD,*† Sarah L. Canham, PhD,‡ and Agnes Iok Fong Lam, PhD§ Abstract: Social capital is a critical resource for physical and mental health among older adults, but few studies have investigated this relationship in Chinese populations, and specifically among those with low socioeconomic status. This study examined the association between depression and cognitive social capital (reciprocity and trust) and structural social capital (social participation) in a community sample of older adults living in public housing in Macau (SAR), China (N = 366). Multivariable linear regressions estimated the associations between dimensions of social capital and depression, while adjusting for potential confounders. Significant inverse associations were found between reciprocity and trust and depression. No association was found between social participation and depression. Poor self-reported health was a robust correlate of depression in all models tested. Future studies are needed to evaluate whether enhancing social capital may reduce depression among Chinese older adults living in poverty. Key Words: Depression, older adults, health, social capital, China (J Nerv Ment Dis 2016;00: 00–00)
D
epression is a common mental disorder affecting Chinese older adults. A recent study revealed a pooled prevalence of 23.6% for major depressive disorder over the past two decades (Li et al., 2014). Poverty and the absence of social capital are two factors independently associated with depression (Cao et al., 2015; Chi et al., 2005; Chou et al., 2004; Zeng and Chan, 2010). However, the role of social capital as a protective resource for depression among Chinese older adults living in poverty is not well established. Social capital has emerged as an important potential protective factor for elderly depression (Cao et al., 2015; Glass et al., 2006; Norstrand and Xu, 2012; Pollack and von dem Knesebeck, 2004). Social capital is a concept symbolizing the resources available through social networks and supports (Bourdieu, 1986). Although there are many definitions and measurement approaches (De Silva et al., 2005; Kawachi et al., 2008), one often cited definition comes from Putnam et al. (1994) seminal work: “features of social organization, such as trust, norms, and networks, that can improve the efficiency of society by facilitating coordinated aims” (p. 167). Cognitive and structural dimensions of social capital follow Putnam’s theorizing (De Silva et al., 2005; Murayama et al., 2012).
*Global and Community Mental Health Research Group, Department of Psychology, Faculty of Social Sciences (E21), University of Macau, Taipa, Macau (SAR), People’s Republic of China; †Department of Health, Behavior & Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; ‡Gerontology Research Centre, Simon Fraser University, Vancouver, Canada; and §Department of Communication, Faculty of Social Sciences (E21), University of Macau, Taipa, Macau (SAR), People’s Republic of China. Send reprint requests to Brian J. Hall, PhD, Global and Community Mental Health Research Group, Department of Psychology, Faculty of Social Sciences (E21), University of Macau, Avenida da Universidade, Taipa, Macau (SAR), People’s Republic of China. E-mail:
[email protected]. Ethical statement: This study was approved by the research ethics review panel of the Macau (SAR) government. This research was carried out in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The authors have stated in the manuscript that each participant provided informed consent before their inclusion in the study. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0022-3018/16/0000–0000 DOI: 10.1097/NMD.0000000000000561
The cognitive dimension involves subjective attitudes of interpersonal trust and social reciprocity, whereas the structural dimension involves observable characteristics of social organizations, such as the number of social groups one belongs to or civic and social participation. Social capital is an important concept particularly among older adults. People lose social ties and functional capacity over time, and may have an increased dependence on social capital to meet their needs (Cannuscio et al., 2003; Cheng et al., 2011; Kahn and Antonucci, 1980). Greater social capital is generally associated with better physical health (Kawachi and Berkman, 2000; Kim et al., 2008), mental health (Almedom and Glandon, 2008), and, in older populations, overall well-being (Cramm et al., 2013). Cognitive social capital was associated with better mental health outcomes in a systematic review of Western studies involving all age groups (De Silva et al., 2005) and in a Japanese study (Hamano et al., 2010). In a study of urban older adults in Mainland China, negative associations were found between cognitive social capital—measured by trust and reciprocity—and depression (Cao et al., 2015). Another study among older Chinese adults in urban and rural settings found social capital to be associated with fewer emotional issues affecting daily life and interpersonal interactions (Norstrand and Xu, 2012). Beyond these two studies, there is limited research evidence supporting the association between social capital and mental health among Chinese older adult populations. Social capital may have particular relevance to Chinese older adults living in poverty. The rapid economic development brought on by social reform, and subsequent transition away from traditional social values, have accelerated the pace of life and weakened family ties, contributing to depression among older adults in China (Shao et al., 2013). This is of particular relevance to social capital theory in Chinese society as it relates to the Chinese cultural concept of Guanxi (Yang and Kleinman, 2008). Guanxi relates to reciprocal relationship ties that are largely instrumental in nature. For Chinese older adults living in poverty, it may be particularly important to gain and maintain this form of capital to secure reciprocal support in light of their reduced economic potential. Research on depression among Chinese older adults has established several correlates. A review of studies in China identified female sex, being unmarried, and low levels of education as being associated with higher prevalence of depressive symptoms (Li et al., 2014). A study in Macau also found being female, poor financial status, low levels of activities of daily living, poor self-rated health, and poor social support to be risk factors for depression among older adults (Chi et al., 2005; Zeng and Chan, 2010). Poor self-rated health status and chronic illness have also been identified as risk factors for depression in older adults in numerous Chinese and Western samples (Huang et al., 2010).
Present Study To our knowledge, no study has previously examined the association between social capital and depression among older adults living in public housing. Macau, a city in Southern coastal China, provides an interesting context for investigation. During the past decade, Macau was transformed from a small regional economy (i.e., a small fishing village) to the largest gaming resort center in Asia. Housing prices have risen dramatically (1108% from 2004 to 2014) whereas the increase of monthly median income has not kept pace (157%) (Direcção dos Serviços de Estatística e Censos, 2016). Older adults in Macau are
The Journal of Nervous and Mental Disease • Volume 00, Number 00, Month 2016
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expected to have the fourth longest life expectancy in the world at over 84 years (Central Intelligence Agency, 2015). They experienced the pre-development period of Macau and the quickly evolving society may have effects on mental health and social capital in this nonWestern context. Senior public housing in Macau is leased or sold (leasing for those with lower economic power) by the government to low-income or socially disadvantaged older adults. Based on income-eligibility requirements in 2011, 6.6% of the local population aged 65 or older were living in public housing (Direcção dos Serviços de Estatística e Censos, 2014). As housing was notably more affordable before the economic boom, those currently residing in senior public housing represent a financially disadvantaged group. In addition, the older adult population in Macau is expected to increase from 7.2% in 2011 to 20.7% in 2036 (Direcção dos Serviços de Estatística e Censos, 2014). An examination of this group is warranted given the need to understand the mental health functioning of this vulnerable group. This study builds upon two previous studies of social capital and mental health among Chinese older adults (Cao et al., 2015; Norstrand and Xu, 2012). We examined both cognitive and structural social capital and its association with depression, while adjusting for previously identified correlates of depression that could confound the relationship between social capital and depression. Previous studies have recognized the significance of financial strain, poor self-rated health, functional impairment, and poor social network/support as correlates of depression in older adults (Chi et al., 2005; Gao et al., 2009; Li et al., 2014; Yu et al., 2012; Zeng and Chan, 2010), but these factors have not been accounted for in past studies exploring the role of social capital on depression in Chinese older adults. Furthermore, our analysis is focused on older Chinese adults living in poverty, which is a unique and vulnerable population that is often neglected. As a secondary aim, we estimated the prevalence of depression as no previous estimate is available for Chinese elders living in public housing. Specific hypotheses are as follows: Hypothesis 1: Being female, older, having less education, and having poorer perceived financial status will be significantly associated with depression among older adults. Hypothesis 2: Lower self-rated health status, functional impairment, and less social contact will be significantly associated with depression after adjusting for sociodemographic variables. Hypothesis 3: Social reciprocity, trust, and social participation will each be associated with less depression, after adjusting for sociodemographic variables, perceived health, functional impairment, and social contact.
METHODS Sample Data for this study were obtained through household face-to-face interviews conducted from July 15 to August 22, 2014. According to the information provided by the Housing Bureau of Macau SAR Government (IHM), there were 667 adults aged 65 or older living in public housing apartments located in seven different buildings in the same residential district “Ilha Verde” during this period. Participants were made aware of the study through announcements posted in the public areas of all seven buildings and through letters mailed to each individual address 2 weeks before the study began. Twenty-one interviewers, who were native Chinese-speaking senior undergraduate students, received intensive training by one of the study senior authors on the administration of interviews, research protocol, and research ethics. Participants were recruited by teams of two trained interviewers, who visited all of the addresses provided by IHM. Up to three attempts were made to conduct the interview for each household. Informed consent was obtained inperson before the interview began, and all interviews were conducted in Chinese. Each completed questionnaire was checked for quality by 2
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a team of five supervisors with a least a master’s degree and experience in household survey research. Continued training and quality assurance checks were made throughout the data collection period. Random call backs to residences confirmed that the participants completed the study. A total of 202 potential respondents were unavailable for interview and 11 refused to participate leaving 366 participants. The interview response rate was 60.9% and the cooperation rate was 96.8% (The American Association for Public Opinion Research, 2015). The confidence level of this survey was 95% with a sampling error of ±3.34%.
Measures Depression The Patient Health Questionnaire-9 (PHQ-9; Kroenke et al., 2001; Yeung et al., 2008) was used to estimate the severity of depression and the prevalence of depression in this study. The PHQ-9 is a widely used 9-item self-report scale, incorporating the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria of depression. Sample items include “little interest or pleasure in doing things,” “feeling down, depressed or hopeless,” and “trouble falling asleep, staying asleep, or sleeping too much.” Compared to the 15-item Geriatric Depression Scale (GDS), the PHQ-9 demonstrated greater specificity as a screening tool for depression among primary care older adults in the United States and is stable across gender and race, and with presence of comorbid chronic illnesses in older adults (Phelan et al., 2010). The use of the PHQ-9 has been validated in other older adult samples (Han et al., 2008; Lamers et al., 2008) and among Chinese older adults (Chen et al., 2010). Responses are based on symptom frequency during the past 2 weeks using a 4-point Likert scale: 0 “not at all,” 1 “several days,” 2 more than half the days,” and 3 “nearly every day.” We calculated a total depression severity score by summing the items. We used a widely validated cut score of 10 or above to estimate the prevalence of depression in the sample (Gilbody et al., 2007; Kroenke et al., 2001; Wittkampf et al., 2007). The internal reliability was 0.78 for the current study.
Social Capital Based on existing conceptualizations of social capital (De Silva et al., 2005; Murayama et al., 2012; Pollack et al., 2004), two items measured cognitive social capital (trust and reciprocity) and two items measured structural social capital (social participation). The majority of urban dwellers in China live in densely populated high-rise apartment buildings. Therefore, trust was measured by asking how much participants agreed with the statement: “Residents in this building are honest and trustworthy.” Trust was similarly measured in a crosssectional study of the association between social capital and mental health with a population-based household sample in Japan (Hamano et al., 2010). Reciprocity was measured by asking: “If there are some problems in your apartment building, you would find other neighbors to deal with it together.” Both trust and reciprocity measures were scored on a 3-point scale: 0 “disagree,” 1 “neutral,” and 2 “agree.” Social participation was measured by two yes or no items related to involvement in community activities and volunteer activities, respectively. These two items were summed to create a composite variable. Internal consistency of these two items (Spearman-Brown coefficient) was 0.60.
Covariates Participants reported their sex, age, education (categorized as no education, primary school, middle school, high school, junior college, and college or above), and perceived financial status (measured by subjective reports on the sufficiency in meeting daily cost of living, ranging from “sufficient” to “not sufficient”). Self-rated health was measured by asking, “Overall, how do you evaluate your personal health condition?” and responses were 1 “poor,” 2 “fair,” 3 “good,” 4 “very good,” or 5 © 2016 Wolters Kluwer Health, Inc. All rights reserved.
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The Journal of Nervous and Mental Disease • Volume 00, Number 00, Month 2016
“excellent.” Functional impairment was measured using an adapted version of the Instrumental Activities of Daily Living Scale (Lawton and Brody, 1969). The scale was first translated and then back-translated into Chinese, and the instrument was pilot tested to determine appropriateness and language clarity for this sample. The final scale contained 20 items, which measured the capacity to perform daily activities. Sample items include “cutting toenails” and “cooking.” Responses were scored on a 5-point Likert scale from “unable to perform” to “able to perform without assistance” and items were summed such that higher scores indicated less impairment. Social contact was measured by a single item of the frequency of visiting friends and responses were scored on a 4-point Likert scale from “never” to “often.”
Depression in Chinese Older Adults
datasets. Over half of the participants were female. The mean age of participants was 72.96 years (SE = 0.53). The majority (76.9%) of our sample reported an income—from all sources, such as personal savings, returns on investment, pension fund, financial support from children and spouses, and all types of government subsidies—of less than MOP 4,000 (approximately USD $500) per month. The median income of the entire Macau population during the same period was MOP 13,000 (approximately USD $1,625). Over half (55.9%) of our participants had no formal education and almost all (96.4%) had no education beyond middle school. Overall, depression symptom severity was low (M = 4.78). Using a cut score for depression of 10 on the PHQ-9, the estimated prevalence of major depression in this sample was 16.39% (95% confidence interval (CI) = 12.58–20.20%). Correlation results revealed several notable findings (Table 1). Female sex was associated with greater social participation (r = 0.17, p < 0.01) and less education (r = −0.35, p < 0.001). Increasing age was associated with lower levels of reciprocity (r = −0.15, p < 0.001) and lower capabilities to carry out daily tasks (r = −0.22, p < 0.001). Older adults with lower perceived financial status were more depressed (r = 0.22, p < 0.001) and reported poorer physical health (r = −0.21, p < 0.001). Less functional impairment was negatively associated with depression (r = −0.33, p < 0.001). Trust was positively associated with reciprocity (r = 0.22, p < 0.001). And notably, all three dimensions of social capital—reciprocity, trust, and social participation—were significantly and inversely associated with depression (p’s < 0.05). The association between social capital and depression was examined (Table 2). Reciprocity and trust were significantly associated with depression in all four models; the higher reciprocity and trust, the lower levels of depression. Even after adjusting for all confounders (sociodemographic variables, perceived health, functional impairment, and social contact) in Model 4, the associations between depression and reciprocity (B = −1.01, p = 0.009 [CI = −1.77, −0.26]) and depression and trust (B = −1.07, p = 0.047, [CI = −2.13, −0.01]) remained significant. The R2 for Model 4 for each analysis was 0.27 (range 0.23–0.34 across 100 multiply imputed datasets) and 0.27 (range 0.22–0.31) for reciprocity and trust, respectively. Social participation was not significantly associated with depression in any of the regression models (R2 for Model 4 was 0.25, range 0.21–0.3). After adjustment for all covariates in the models, perceived health was a robust correlate of depression in all models of social
Data Analysis Multiple imputation was used to estimate item-level missingness in the sample. In total, 100 multiply imputed datasets were created using chained equations in STATA MP 12.1 (StataCorp, 2011). Models were analyzed in each of these 100 datasets separately, and their results combined, using STATA mi: estimate command. The average Model R2 values and the range in these values across imputed data sets were estimated using the user-written mibeta command. We used multivariable linear regression to measure the associations between dimensions of social capital and depression symptom severity. Four models evaluated the role of each dimension of social capital (reciprocity, trust, and social participation were each tested separately), after adjustment for potential confounders. Model 1 controlled for sex, age, education, and perceived financial status. In Model 2, we controlled for the variables in Model 1 and perceived health. In Model 3, we controlled for the variables in Model 2 and functional impairment. To differentiate the potentially confounding influence of social contact from that of social capital, dichotomized responses (yes or no, with sometimes and always as yes) were controlled for in Model 4 in addition to the variables in Model 3.
RESULTS Table 1 shows the means, standard errors, and correlations among the variables. Bivariate analyses between sex and other variables were conducted using point biserial correlations. Standard deviations are not available as we present the averaged sums for all imputed
TABLE 1. Descriptive and Correlation Among Major Study Variables (N = 366) M or % SE 1. Sex (female (%)) 57.1 2. Age 72.96 3. Education 1.63 4. Perceived 1.97 financial status 5. Perceived health 2.75 6. Functional 73.00 impairment 7. Social contact 1.10 8. Reciprocity 2.58 9. Trust 2.68 10. Social 0.52 participation 11. Depression 4.78
1
2
3
0.03 0.53 0.04 0.04
0.18* −0.35*** −0.11* −0.08 −0.06
0.05 0.47
−0.08 −0.11*
0.05 0.04 0.03 0.04
−0.02 −0.06 0.011 −0.03 −0.15*** 0.07 0.09 −0.09 −0.05 0.17** 0.06 −0.03
0.28
0.09
−0.04 −0.22***
0.03
4
5
6
7
8
9
10
−0.06 0.06 0.14**
−0.04
−0.21*** −0.11* −0.04 −0.05 −0.04 −0.12* 0.22***
0.35*** 0.21*** −0.03 0.03 0.03
0.33*** 0.12* 0.06 0.14**
0.05 0.09 0.15**
−0.42***
−0.33***
−0.29***
0.22*** 0.07 −0.13*
0.09 −0.15* −0.11*
Standard deviations for study variables are not available as these are results from multiply imputed data. Correlations between sex and all other variables specified with point biserial correlations. Correlations based on pairwise analysis of incomplete data. *p < 0.05; **p < 0.01; ***p < 0.001.
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TABLE 2. Association Between Social Capital and Depression Symptom Severity
Depression Model 1 Model 2 Model 3 Model 4
Reciprocity B (95% CI)
Trust B (95% CI)
Participation B (95% CI)
−1.04 (−1.88, −0.19)* −1.14 (−1.91, −0.37)** −1.03 (−1.80, −0.27)** −1.01 (−1.77, −0.26)**
−1.31 (−2.44, −0.17)* −1.21 (−2.28, −0.13)* −1.15 (−2.21, −0.09)* −1.07 (−2.13, −0.01)*
−0.71 (−1.45, 0.04) −0.66 (−1.35, 0.04) −0.46 (−1.15, 0.23) −0.34 (−1.03, 0.35)
*p < 0.05; **p < 0.01; ***p < 0.001. Model 1: adjusted for gender, age, education, and perceived financial status. Model 2: adjusted for variables in Model 1 + perceived health (B = −1.20, p < 0.001). Model 3: adjusted for variables in Model 2 + functional impairment (B = −1.71, p < 0.001). Model 4: adjusted for variables in Model 3 + social contact (B = −1.62, p < 0.001). F statistics for Model 4 are F(8, 344.6) = 12.78 for reciprocity, F(8, 342.8) = 12.01 for trust, and F(8, 348.1) = 12.19 for participation, all p < 0.001.
capital: reciprocity (B = −1.62, p < 0.001, [CI = −2.19, −1.05]), trust (B = −1.55, p < 0.001, [CI = −2.1, −0.97]), and social participation (B = −1.57, p < 0.001, [CI = −2.15, −0.99]). A sensitivity analysis was conducted (data not shown) on the listwise sample to compare differences between the imputed estimates and the listwise sample and no qualitative differences emerged.
DISCUSSION The present study demonstrated that social capital was inversely associated with depression in a sample of Chinese older adults living in social housing. Among the four risk factors included in hypothesis 1, only perceived financial status was significantly associated with depression. No significant relationship was found between depression and sex, age, or education, providing only partial support for hypothesis 1. Hypothesis 2 was supported as perceived health status, functional impairment, and social contact were all significantly related to depression. Perceived health status had the largest association with depression, supporting previous research that has found physical health to influence emotional health in later life (Huang et al., 2010; Niti et al., 2007). Hypothesis 3 was partially supported. Cognitive social capital, measured by reciprocity and trust, was inversely associated with depression. Though cognitive social capital has previously been found to be inversely and strongly associated with mental health (De Silva et al., 2005), the current study provides additional support for this association in a Chinese older adult sample. We identified a pattern similar to results from a previous older Chinese sample, which showed that trust and reciprocity were associated with lower depression after adjusting for sex, age, education, and income (Cao et al., 2015). However, our study extends the literature by also adjusting for poor self-rated health and impairment, and tests this association among low-income Chinese older adults. The association of trust with better mental health in an adult (including older adults) Japanese sample (Hamano et al., 2010) is also comparable to the lower depression observed in our sample. This finding is also similar to results from a sample of U.S. older adults, but only partly converges with German older adults in which reciprocity and social participation, but not trust, were inversely associated with depression (Pollack and von dem Knesebeck, 2004). Social participation was not related to depression in our sample, which is partly consistent with previous research with Chinese older adults (Cao et al., 2015; Chiao et al., 2011). Similar to our study, Cao et al. (2015) found no effect of social participation on depression as measured by the number of volunteer groups, hobby clubs, religious clubs, political groups, women’s groups, and sports clubs participants joined in the past 5 years. In contrast, Chiao et al. (2011) found significant effects of social participation on depression using a similar measurement, with the first four identical to Cao et al. (2015) and added elder community associations. Although only two items, community 4
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activities and volunteer activities, were used in the current study, they are broader and perhaps more inclusive of social participation than the specific activities measured in the other two studies. Community activities, in particular, is a broad category encompassing a diverse range of activities provided by social organizations in China. Questions remain as to the mechanisms that drive the association between social capital and mental health outcomes. Kawachi and Berkman (2000) suggested that individuals who live in communities that lack social capital could suffer from social isolation and thus negative health outcomes. However, we found a significant relationship between social contact and all dimensions of social capital. Even after adjustment for social contact, reciprocity and trust remained significantly associated with depression, suggesting that social isolation may not be driving this relationship. Moreover, social participation was not associated with depression in this study. Therefore, the influence of social capital is likely a more specific resource than social contact alone. In terms of the cognitive dimension, social capital may reduce depression indirectly through social support (Cao et al., 2015; Kawachi et al., 2000). More research of social capital incorporating social support should investigate this possibility. Guanxi, common in Chinese society, is a concept related to social capital, given that it encompasses the social networks and social bonds that provide the context for resource exchange (Harpham et al., 2002; Qi, 2013; Yang and Kleinman, 2008). Although speculative, older adults living in public housing are likely to utilize guanxi networks in terms of obtaining information to address their everyday needs within their tightly bound building community. Compared to older adults without this information resource, those who have access are better able to take advantage of a wider range of instrumental support from community services and public resources. However, guanxi is also heavily associated with the obligatory exchange of symbolic favors that facilitate social network formation and maintenance. This explicit focus on resource exchange is not integrated into the Western concept of social capital to which we refer in this paper. Norstrand and Xu (2012) remind us that the two forms of capital were not the same due to the obligatory and instrumental nature of guanxi. As social capital refers broadly to social resources, a question arises as to how researchers should reconcile guanxi capital and social capital when conceptualizing the role of social resources with Chinese or non-Western samples (Qi, 2013; Yang and Kleinman, 2008). For our study population, material resource exchange may not be the defining feature of their guanxi network because of their relatively low economic capital. Rather, it is likely that trust in members of their network can provide a sense of security and belonging which contributes to positive impact on emotional well-being and can act as a protective factor against health deterioration. As most previous research on guanxi has been done from a business or organizational perspective, future research should explore the potential complementary aspects of guanxi and social capital theory (Qi, 2013) to enable further examinations of the complexity of guanxi as it relates to mental health. This will allow © 2016 Wolters Kluwer Health, Inc. All rights reserved.
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The Journal of Nervous and Mental Disease • Volume 00, Number 00, Month 2016
research to provide more culturally specific insights into forms and uses of social resources and networks in the protection of health. Beyond these research implications, practical implications can be drawn in the area of public health. Promotion of social capital among older adults, particularly the cognitive dimensions of reciprocity and trust, can now be supported with empirical findings. Older adults living in public housing make up a subpopulation with specific socioeconomic characteristics under government monitoring, making them a potential group for pilot social capital enhancement programs. For instance, interventions using behavior change techniques have been successful in increasing volunteer activity among older community-dwelling adults (Warner et al., 2014). Community-based interventions to increase trust and reciprocity among older adults could include opportunities for social participation or interpersonal relationship strengthening. A secondary aim of the study was to estimate the prevalence of depression. Our current estimate (16.39%) was higher than previous studies in Macau (10.4%; Zeng and Chan, 2010) and Hong Kong (12.5%; Chi et al., 2005), but lower than samples from Mainland China (23.6%; Li et al., 2014). However, these previous studies used the Geriatric Depression Scale (GDS) and the Center for Epidemiologic Studies Depression Scale (CES-D), so direct comparison needs to be taken in caution. Moreover, our sample was restricted to older adults living in public housing and might not reflect the general older adult population living in Macau. Future research should determine the prevalence of depression among the general population of older adults in Macau. Nonetheless, the current study identified a large proportion of Chinese older adults who may have depression, suggesting the need for follow-up work in this area. Though this study is the first to assess the association between social capital and mental health among Chinese older adults living in poverty, it is not without limitations. First, the cross-sectional design does not allow for temporal investigations of the associations in this study and health is a fluctuating state, especially among older adults. A second limitation involves the single-item measure of social contact, which asked about the frequency of visiting friends. Indeed, other social contacts (e.g., family) are valuable to older adults and future research should consider a broader range of potential social contacts. A third limitation is the use of the single-item measure of the dimensions of cognitive social capital. These data stem from a larger study in which participant fatigue was considered in the measurement design. Asking participants about trust and reciprocity only within the context of their apartment building may miss important aspects of the capital available within their broader neighborhood, and other social networks within the Chinese context (Cornwell et al., 2008). However, apartment buildings in our study are tall 20 plus floor mega structures, and future research should explore the definition of neighborhood within this densely populated urban environment and its relation to health. Although the measures we used are consistent with the majority of research in this area (Cao et al., 2015; Hamano et al., 2010; Kawachi and Berkman, 2000; Pollack and von dem Knesebeck, 2004), increased reliability of the measures could be obtained after the development and validation of social capital instruments among Chinese older adults. We should also note that the participant response rate was 61% for the current study. This may have introduced bias in our analysis, as older adults who are most depressed, for example, may not have participated.
CONCLUSION Despite these limitations, our study presents novel evidence of the association between social capital (reciprocity, trust, and social participation) and depression among older Chinese adults living in public housing. Few previous investigations have explicitly linked social capital and health among Chinese older adults. Older adults are expected to comprise 20% of the population by 2035 (Peng, 2011) and identifying key areas for potential intervention is an important public health priority
Depression in Chinese Older Adults
(Li et al., 2014). Our results suggest that social capital is an important area of consideration for enhancing the mental health of poor urbandwelling Chinese older adults. ACKNOWLEDGMENTS This research was supported by the Public Opinion Research Group of the Department of Communication of the University of Macau. The authors thank Juliana Yuncg, Elenna Mo, Ray Wong, Ung Hou Pang, Angela Ma and Jazz Cheong for their assistance with data collection. Portions of this work were presented at the ARUPS conference in Singapore, May 2015, by the first author. The authors also thank the Honors College, University of Macau, for their support. This work was supported by the Research and Development Affairs Office (R&DAO), University of Macau, under grant MYRG201500124-FSS and MYRG2015-00109-FSS. DISCLOSURE The authors declare no conflict of interest. REFERENCES Almedom AM, Glandon D (2008) Social capital and mental health: An updated interdisciplinary review of primary evidence. In Kawachi I, Subramanian SV, Kim D (Eds), Social capital and health (pp 191–214). New York, NY: Springer. Bourdieu P (1986) The forms of capital. In Richardson J (Ed), Handbook of theory and research for the sociology of education (pp 241–258). New York, NY: Greenwood. Cannuscio C, Block J, Kawachi I (2003) Social capital and successful aging: The role of senior housing. Ann Intern Med. 139:395–399. Cao W, Li L, Zhou X, Zhou C (2015) Social capital and depression: Evidence from urban elderly in China. Aging Ment Health. 19:418–429. Central Intelligence Agency (2015) The World Factbook. Washington, DC: Central Intelligence Agency. Available at https://www.cia.gov/library/publications/ the-world-factbook/geos/mc.html. Chen S, Chiu H, Xu B, Ma Y, Jin T, Wu M, Conwell Y (2010) Reliability and validity of the PHQ-9 for screening late-life depression in Chinese primary care. Int J Geriatr Psychiatry. 25:1127–1133. Cheng S-T, Li K-K, Leung EMF, Chan ACM (2011) Social exchanges and subjective well-being: Do sources of positive and negative exchanges matter? J Gerontol B Psychol Sci Soc Sci. 66B:708–718. Chi I, Yip PSF, Chiu HFK, Chou KL, Chan KS, Kwan CW, Conwell Y, Caine E (2005) Prevalence of depression and its correlates in Hong Kong’s Chinese older adults. Am J Geriatr Psychiatry. 13:409–416. Chiao C, Weng LJ, Botticello AL (2011) Social participation reduces depressive symptoms among older adults: An 18-year longitudinal analysis in Taiwan. BMC Public Health. 11:292. Chou KL, Chi I, Chow NWS (2004) Sources of income and depression in elderly Hong Kong Chinese: Mediating and moderating effects of social support and financial strain. Aging Ment Health. 8:212–221. Cornwell B, Laumann EO, Schumm LP (2008) The social connectedness of older adults: A national profile. Am Sociol Rev. 73:185–203. Cramm JM, van Dijk HM, Nieboer AP (2013) The importance of neighborhood social cohesion and social capital for the well being of older adults in the community. Gerontologist. 53:142–152. De Silva MJ, McKenzie K, Harpham T, Huttly SRA (2005) Social capital and mental illness: A systematic review. J Epidemiol Community Health. 59:619–627. Direcção dos Serviços de Estatística e Censos (2014) Tendências e desafios do envelhecimento da população. Macau: Direcção dos Serviços de Estatística e Censos. Direcção dos Serviços de Estatística e Censos (2016) Statistics Database. Macau: Direcção dos Serviços de Estatística e Censos. Available at http://www.dsec.gov. mo/TimeSeriesDatabase.aspx. Gao S, Jin Y, Unverzagt FW, Liang C, Hall KS, Ma F, Murrell JR, Cheng Y, Matesan J, Li P, Bian J, Hendrie HC (2009) Correlates of depressive symptoms in rural elderly Chinese. Int J Geriatr Psychiatry. 24:1358–1366.
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Copyright © 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.