Depression in Older People in Rural China

Background  In Western countries depression is the most common psychiatric condition in older persons and related to low socioeconomic status and low social supports. Along with social deprivation, the rural communities in China retain many Chinese traditions that involve high levels of social supports. Studying such a population might offer insights into the cause and prevention of depression that may be applicable in developing and developed countries.

Methods  Using a cross-sectional, household-based, community survey in rural China, we aimed to determine the prevalence of and risk factors for depression among older people who had a low income (mean annual per capita income of about US $280) and high social support in 16 villages in Anhui Province. Participants included 754 men and 846 women aged 60 years or older. Depression was diagnosed using the Geriatric Mental State and the Automated Geriatric Examination for Computer Assisted Taxonomy. Risk factors, collected from the standard questionnaire and physical measurements, were examined in a stepwise multiple logistic regression model.

Results  The prevalence of depression (world age standardized) was 6.0% (95% confidence interval [CI], 4.8%-7.3%). Of all persons, 1374 older persons (85.9%) living with family members. Depression was significantly and independently associated with female gender, low family income, lack of social support, relationship problems, poor health status, and adverse life events in the past 2 years. The risk of depression increased in those eating meat less than once a week (multiple-adjusted odds ratio, 2.20; 95% CI, 1.20-4.03), not watching television (odds ratio, 1.76; 95% confidence interval, 1.03-3.00), and having undetected hypertension (odds ratio, 1.78; 95% CI, 1.05-3.01).

Conclusions  Older people in rural China have a lower risk of depression than those in Western countries. Low socioeconomic status showed a “dose-response” relationship with depression, and social supports were much more common, which were protective for depression. Further exploration of Chinese culture and tradition may yield universal insights into preventive factors for depression in older people.

Depressive disorders are the most common psychiatric condition found in older people in the Western world.¹ The functional impairment, decreased quality of life, and increased mortality caused by depression impose an immense burden on individuals, communities, and health services. Globally, depression accounts for as much disease burden as ischemic heart disease,^2,3 and it has been projected to become the second most common cause of disability by 2020.⁴ In Western countries, depression in older persons is related to low socioeconomic status (SES), low social support, poor health status, disability, adverse life events, and female gender.^5-7 In many Western populations, low social position is associated with low social support.⁸

With an estimated population of 1.3 billion, China is the most populous country in the world. Since its reform in 1978, China has experienced rapid economic growth and an increase in life expectancy, and the population as a whole is aging.⁹ In rural areas, where 900 million peasants live, the mean annual income (range, US $140-$340) is about 2 to 5 times lower than that in urban areas (range, US $412-$652).⁹ Along with low SES and deprivation, rural communities retain many Chinese traditions that involve high levels of social support. Living with family members, having contact with neighbors and family outside the home, and welcoming community participation and help when needed are important aspects of social support. However, it is not known how common depression is or which risk factors operate among the rural older population in China. Studying such a low-income population that have high social support might offer insights into the cause and prevention of depression that are applicable in developing and developed countries. We, therefore, investigated the prevalence of depression among older people in rural China, examined its risk factors, and explored differences between China and Western countries.

In 2003, we selected all 16 villages in the Tangdian district of Yingshang County, Anhui Province (mideastern China), as our field of study (Figure), representing a typical rural community. The district included 34 700 residents within an area of about 600 km². More than 95% of the population were agriculturalists; the main work of peasants was producing rice (paddy) and wheat. The mean annual per capita income was approximately 2300 Renminbi ([RMB] about US $280). More than 20% of the households lived in mud houses, about 75% had no telephone, and approximately 80% had no television set. The district had roads constructed with sand and stone, but it had no railway or industry. Within each village, there were usually 4 small subvillages, where 100 to 150 households were clustered, with a mean distance of 5 m between households. Our target population included persons 60 years or older who had lived in the villages 5 years or longer. Based on the sample size in a previous study¹⁰ of urban China and on an estimated mean ± SE prevalence of depression of 5.5% ± 1.1% (at 95% confidence intervals [CIs]), we opted to investigate 1700 older persons in the community. We randomly chose 2 subvillages from each village for the survey.

From a residency registration list in the district, we identified 1709 eligible older persons and successively visited the households accompanied by local subvillage leaders. After explaining the aims and methods of the study, 1624 persons agreed to participate in the investigation. Beginning on April 1, 2003, our 8-member trained survey team interviewed them. Permission for interview was obtained from each person or from an adult guardian, and 1600 participants (754 men and 846 women) were successfully interviewed at home. The response rate was 93.6% (1600/1709) after excluding the 24 participants with incomplete questionnaires. The survey team completed all data collection by April 30, 2003. The study was approved by Anhui Medical University, Hefei, China, the district government, and village residency committees.

We defined depression using the Geriatric Mental State (GMS) and the Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT),^11,12 which have been widely used in western European countries¹ and in parts of Asia, South America, and Africa.¹¹ The Chinese version of the GMS has been validated among older Chinese in Singapore, Hong Kong, Taiwan, and mainland China.^10,11 Systematic training of the survey team in the use of the GMS was done before the interviews, as previously described.¹⁰ In brief, 2 research workers were trained in 2001 in the use of the GMS at the Institute of Psychiatry, Beijing Medical University, Beijing, China, by an investigator who had attended a GMS-AGECAT course in Liverpool, England. They then trained the 8 members of our survey team. To identify persons with depression at a level of severity warranting intervention,¹² the GMS data were analyzed using the AGECAT, which has been validated in different countries,¹¹ including China.¹⁰ To ensure the reliability of the GMS-AGECAT used in the rural community, 2 consultant psychiatrists from Hefei Psychiatric Hospital, a teaching hospital of Anhui Medical University, reexamined the depression cases identified by the GMS-AGECAT and a matched number of control subjects without mental illness who were randomly selected according to proximity to the cases’ home addresses. Double-blind methods were used for the validation of the GMS-AGECAT depression diagnoses.

The interview materials, apart from the GMS, included a general health record that was derived partly from a previous health and risk factor questionnaire,¹³ the Minimum Data Set in the Medical Research Council Ageing in Liverpool Project-Health Aspects (MRC-ALPHA) Study,⁷ and the Scottish WHO MONICA surveys.¹⁴ Data obtained included the following: (1) SES (including educational level, occupation, and self-assessed family income), (2) social support, (3) relationships, (4) histories of disease and medications and self-assessed physical health, (5) adverse life events occurring in the past 2 years, and (6) other information (including dietary intakes¹³ and hobbies). We measured social support in the 3 domains of quality (good relationships with neighbors, parents, or others; ease in acquiring friends; and available help when needed), quantity (marital status, residence with family members, frequency of visiting children or other relatives, and contact with neighbors or friends in the village), and community participation (having any religious belief and taking part in activities and participating in community activities for seniors). Structure refers to the number of persons in the social network and the frequency of contacts with them.⁷ According to standard procedures,¹⁴ we measured systolic and diastolic blood pressure, as well as height, weight, and waist circumference, for all participants.

The SPSS statistical package (Windows version 11.0; SPSS Inc, Chicago, Ill) was used for data analysis. The prevalence rates of depression with 95% CIs among men and women were calculated, and differences in gender and age (in 5-year increments to ≥80 years) groups were assessed by χ² test. The prevalence rate was age standardized using the world population in 2003 (available at: http://www.census.gov/ipc/www/idbagg.html, accessed May 2004). Agreement on depression diagnoses between the GMS-AGECAT and the psychiatrists was validated by κ test. The association of depression with risk factors was explored using a logistic regression model, with adjustment for age and gender.¹⁵ A stepwise multiple logistic regression model was used to calculate odds ratios (ORs) and 95% CIs to assess the independent effects of risk factors for depression. For comparison with the MRC-ALPHA Study,⁷ a prevalence relative risk of depression and some risk factors among the Chinese older population were estimated using a Poisson regression model.

We found that 1395 participants (87.2%) were illiterate, 134 (8.4%) had a primary school education, 52 (3.3%) had attended secondary school, 17 (1.1%) had a high school diploma, and 2 (0.1%) had a college education. Ninety-five depressed cases (26 men and 69 women) were diagnosed. The crude prevalence rate of depression was 5.9% (95% CI, 4.8%-7.2%), with a 3.5% (95% CI, 2.3%-5.0%) prevalence among men and an 8.2% (95% CI, 6.4%-10.2%) prevalence among women (P<.001). Prevalences of depression among persons in the age groups 60 to 64, 65 to 69, 70 to 74, 75 to 79, and 80 years or older were 4.5% (95% CI, 2.8%-7.0%), 8.3% (95% CI, 5.5%-11.9%), 5.5% (95% CI, 3.4%-8.5%), 5.6% (95% CI, 3.3%-8.9%), and 6.4% (95% CI, 3.6%-10.3%), respectively (P = .30). Using the world population in 2003, the age-standardized prevalence of depression was 6.0% (95% CI, 4.8%-7.3%), with a 3.4% (95% CI, 2.0%-4.7%) prevalence among men and an 8.5% (95% CI, 6.5%-10.5%) prevalence among women.

There was good agreement on depression diagnoses between the GMS-AGECAT and the psychiatrists. Of 95 cases and their 95 controls, 86 cases and 87 controls were reexamined by the 2 psychiatrists. Agreement was 82.1% (142/173), with a κ statistic of 0.64 (P<.001). The sensitivity and specificity of the GMS-AGECAT depression diagnoses were 82.6% (71/86) among cases and 81.6% (71/87) among controls.

Table 1 gives the frequencies of risk factors and the age- and sex-adjusted ORs for depression in our total population of older persons in the Tangdian district. One thousand three hundred seventy-four older persons (85.9%) lived with family members. Depression was significantly related to female gender, age between 65 and 69 years, and lower weight (but not waist circumference). It was further significantly related to low SES, lack of social support, problematic relationships, poor health, and adverse life events occurring in the past 2 years.

Regarding SES indicators, the percentages of those eating meat once a week or more among participants with very satisfactory or satisfactory, average, or poor family incomes were 59.5%, 32.7%, and 15.1%, respectively; the percentages of those watching television were 60.8%, 47.2%, or 31.0%; and the percentages of those watching performances were 44.8%, 42.9%, and 24.6% (all trend P<.001). All social support and relationship measures, except having any religious belief, were significantly related to low family income (data available from the author); for example, 76.9%, 50.9%, and 38.8% of participants in the 3 categories of family income, respectively, had good relationships with others and ease in acquiring friends.

In a stepwise multiple logistic regression model, depression was significantly associated with female gender, low family income (in a “dose-response” manner), less consumption of meat, absence of watching television, residence with parents or alone, bad relationships with neighbors, poor health status, undetected hypertension, and adverse life events in the past 2 years (Table 2).

Among a poor rural older population in China, we found a lower prevalence of depression than in Western countries. Within this population (94.9% of whom were peasants), the risk of depression was associated with low family income and other indicators of social position. Despite their low SES, high levels of social support in this community may contribute to the lower risk of depression.

The main strengths of the study were a typical rural community setting in China with low SES and high social support, use of the GMS-AGECAT to diagnose depression (validated by Chinese psychiatrists as having a similar κ statistic as in previous studies^10,11,16), and a high response rate to face-to-face interviews using standard questionnaires to collect data on risk factors (including blood pressure and physical measurements). We selected participants from 16 villages in one region of the country. Although the study region had levels of economic development and modernization comparable to those in other provinces of rural China, caution should be exercised in generalizing our findings to China’s 90 million rural older inhabitants. A further limitation of our study was the cross-sectional design, limiting inference on causal direction. However, the risk factor associations we observed were consistent with those in longitudinal studies^5,6,15 among Western populations. Most of the putative risk factors were self reported (as in many Western studies), and this may lead to bias if depressed participants are more likely to report adverse data. In Western populations, assessments of risk factors (eg, median household income) are available from computerized records, which are nonexistent in poor rural populations. However, we sought multiple indicators of measuring deprivation (eg, less consumption of meat) and obtained objective measures of health status (eg, blood pressure, weight, and waist circumference). Consumption of meat and blood pressure measurement were significant variables in the multiple logistic regression analysis.

The population that we studied was poor. Despite this, 33.3% of the participants rated their family income as satisfactory or very satisfactory. Within this population, deprivation was associated in a dose-response manner with depression, suggesting the importance of SES. This supports a causal role for SES in the etiology of depression in older people within a rural Chinese population.^5,15 In a study¹⁰ of urban China, there was less poverty and, consistent with this, a lower 2.2% prevalence of depression. Social factors may have various effects at different life stages. British data show that low SES in middle age is an important predictor of morbidity, including depression,¹⁷ and our participants in middle age would have been poorer still before the reform in China. One wonders why our much poorer population had a lower prevalence of depression than populations in western Europe (range across 7 countries, 8.8%-23.6%, according to the GMS-AGECAT¹). Three possible reasons may be considered. First, there were higher levels of social support and positive life values among older people in China. Second, working and living environments in rural areas were more relaxed (eg, less stressful work and more physical farming activity). Third, the causes of diseases within populations may differ from the factors that explain differences between populations. Nevertheless, the finding of a dose-response relationship between deprivation and depression in our population suggests that strategies for addressing depression in older people are needed in developed and developing countries.

A higher risk of depression was associated with eating less meat and not watching television, which were related to low family income and were common in rural China. Less consumption of meat may be linked to low family income, a waning appetite, or a low intake of fish.¹⁸ The absence of television watching could be due to insufficient money to buy a television set or a lack of interest in entertainment or newscasts, further isolating one from society and exacerbating depression. For example, in our study population 63.1% of those not participating in senior community activities during leisure time did not watch television, compared with 45.7% of those participating (P<.001). Nevertheless, low family income, consumption of less meat, and absence of television watching were significant in the stepwise multiple logistic regression model, suggesting that all 3 variables are operative in depression.

We speculate that aspects of Chinese culture and tradition may prevent depression in older people. For example, Chinese adages include “Bringing up a son will prevent aging” and “One should not go far away from his or her parents.” Although genetics may contribute to the low prevalence of depression among rural Chinese, it is unlikely to explain the prevalence differences between Chinese and Western older populations. Older Chinese persons living in the United Kingdom have a much higher 13.0% prevalence of depression,¹⁹ consistent with the observation that Chinese emigrants adopt some aspects Western lifestyles, including less social support. Table 3 compares older populations in Yingshang, China, and in Liverpool,^7,16 revealing large differences in social support measures. Fewer older people in China lived alone, and more of them visited children or other relatives and participated in community activities. Although the social and cultural significance of these factors is complex and cross-cultural comparisons should be made with caution, our data are consistent with a protective role of social support in rural China. The high level of social support and the low prevalence of depression imply that environmental factors may be operative in the cause of depression among older Chinese.

In Western older populations, poor physical health has been found to be a strong risk factor for depression.^6,7 Our study identified a relationship between poor health status and depression among Chinese older populations. In rural China, the primary care system is mainly carried out at clinics staffed by minimally trained medical personnel (“barefoot doctors”). In our community, there was no medical insurance for agriculturalists, and the peasants had to pay 100% of their medical fees. Poor health status was reported in 22.4% in our rural population, compared with 11.6% in urban China.¹⁰

Interestingly, we found that depression was significantly associated with undetected hypertension. The reason is unclear and needs further investigation. Undetected hypertension may be associated with deprivation, minimal access to health care, or vascular complications in the brain. Hypertension screening among older populations may be warranted for preventing depression and cardiovascular disease.

The lower prevalence of depression among our population compared with Western populations is unlikely to result from chance or bias. Large prospective studies are required to investigate geographic variations, environmental and genetic risk factors, and management of depression among older people across China. Exploration of Chinese culture and tradition may yield insights into preventive factors for depression in older people, of interest to Chinese and Western populations.

Correspondence: Ruoling Chen, MD, PhD, Department of Epidemiology and Public Health, Royal Free and University College Medical School, University College London, 1-19 Torrington Pl, London WC1E 6BT, England (ruoling.chen@ucl.ac.uk).

Accepted for Publication: May 1, 2005.

Financial Disclosure: None.

Funding/Support: This study was supported in part by grant 574006.G603/22085 from The Royal Society and the Universities’ China Committee, both in London. Dr Hemingway is supported by a National Public Health Career Scientist Award from the Department of Health, London.

Previous Presentation: This study was presented at the 132nd Annual Meeting of the American Public Health Association; November 10, 2004; Washington, DC.

Acknowledgment: We thank the participants and all who took part in the survey, especially Yi Dong, MD, and Haitao Xia, MD, for their validation of depression diagnoses.