In this study, we examined the association between marital status, physical activity, and depression in Korean elderly aged 65 or older using the KNHANES data (2014, 2016, and 2018 surveys). With the recent worldwide increase of health concerns regarding geriatric depression, this study is expected to provide basic information for managing groups of elderly people at high risk for depression.
We found a gender-dependent association between marital status and depression, the risk of depression being higher in spouseless older men than women (men: OR = 1.89, 95% CI = 1.05-3.39; women: OR = 1.35, 95% CI = 1.01-1.82). This result suggests that in gender, the absence of a spouse poses a high risk of depression. Depression was also associated with education, gender, household income, self-rated health, and chronic disease. We performed regression analysis by combining the factors of marital status and physical activity and found that the risk of depression was 1.65 times higher for elderly spouseless individuals who performed physical activity. Among elderly men who performed physical activity, those living alone (including unmarried, divorced, widowed, and separated) were 2.65 times more likely to suffer from depression than the those living with their spouse.
In terms of gender, a previous study showed that women aged 60 or older are at higher risk of depression than older men (19). The risk of depression increases in adulthood owing to gender-role stereotypes and inequalities between women and men (2, 14). The specific factors associated with depression may vary due to the cultural differences among countries. Confucian cultures can have a significant impact on depression mediated by the inequality in gender roles (14, 20). Among the demographic characteristics, economic factors and education levels also affect depression, with low household income and education levels increasing the risk of depression (21). In general, highly educated people can alleviate depression by enjoying more opportunities to participate in various social activities, thanks to their high awareness and wide interests (21).
In present study, older individuals with poor self-rated health and those with chronic diseases had high risk of depression. The risk of depression was associated in the elderly with poor self-rated health in both genders (men: OR = 7.77, 95% CI = 2.41-24.99; women: OR = 8.89, 95% CI = 3.62-21.86). Furthermore, elderly individuals with more than three chronic diseases were 1.52 times more at the risk of depression than those without chronic diseases. Previous studies reported that self-rated health was a major predictor of depression in the elderly (22).
Physical activity, age, occupation, current smoking status, or high-risk alcohol drinking were not associated with depression in this study. The differences with the results of previous studies might depend on the number of participants and the target age group. We analyzed 4,134 participants from three years of data, among whom only 318 (7.7 %) had depression.
We found that marital status affected geriatric depression more than physical activity. The analysis of the combined association between marital status and physical activity with depression showed that elderly individuals living alone and performing physical activity had a 1.65-fold higher risk of depression than the reference group (Figure 1). Specifically, older physically active men without spouse had a 2.65-fold higher risk of depression than the reference group. This result is in agreement with those of previous studies showing that older spouseless men are at higher risk of depression than spouseless older women (12, 13). It is well known that older adults who feel loneliness or live alone (unmarried, divorced, widowed, or separated) are more prone to depression than those who do not (11). Social isolation and loneliness also limit physical activity and cause prolonged sedentary behavior (23). According to Jang et al.’s study showed that husbands receive more physical and emotional support from their wives (14). Furthermore, as is typical in patriarchal Oriental family cultures, Korean older men tend to rely more on their spouses after retirement, so they suffer more grief after they separate from their spouses (14). Therefore, the awareness of fixed gender roles should be improved in Korea, and it seems necessary to enable the elderly to actively participate in social activities in order to ease the burden of depression among older adults (5).
Although this study found no association between physical activity and depression, many previous ones reported that regular physical activities such as aerobic activity and flexibility exercises were effective lifestyle interventions to prevent depression in the elderly (6, 7, 24). This effect is due to the fact that physical activity enables social support, such as communication with people and enhanced friendships, along with the promotion of psychological stability and health conditions (6). Wen et al.’s study indicated that low levels of exercise, defined as 15 minutes per day or 90 minutes per week at moderate intensity, were beneficial in preventing disease (25). Therefore, exercise intensity and duration for this age groups should be continuously studied to further support policies to prevent depression and all-cause mortality (8).
The present study had several limitations. First, three years of data were collected, but the sample size was relatively small. Out of 4,134 people analyzed, only 318 (7.7%) had depression, and some variables could not be analyzed because, for example, there were no elderly women with high-risk alcohol consumption among the participants. Therefore, it is necessary to construe the results carefully. Second, this is a cross-sectional study, so that we cannot prove any causal effect of marital status or physical activity on depression. Third, standards for physical activity for the elderly with world-proven reliability are not available and could not be applied. Fourth, the KNHANES is a self-reporting survey of the general population in South Korea, based on subjective answers by the participants and on limited quantitative measurements.
Despite these limitations, the study has several strengths. First, the KNHANES is a relatively large national community-based survey. Second, this study found that elderly people without spouse had a higher risk of depression, with differences between the genders. Third, since the chosen independent variables have a simple intuitive meaning, the results can be used as basic data to encourage social participation in the prevention of depression among elderly.