The negative effects of discrimination on health are now well established. Several studies have reported that discrimination is associated with poor health outcomes, including obesity [1
], depression [2
], and suicidal ideation [3
Most previous studies exploring the health effects of discrimination have focused on “minority populations,” such as immigrants [4
], ethnic minorities [5
], and sexual minorities [6
], as they are frequently exposed to discrimination. However, members of the general community could also experience discrimination or unjust treatment due to gender or socioeconomic position. In fact, a number of studies have shown that members of so-called “majority populations” could be more vulnerable to discrimination, since they are not as accustomed to discrimination as minorities are [6
Particularly in countries with collectivistic cultures such as Japan and Korea, members of the general community are not in the “discrimination safety zone.” Previous studies have shown that up to 40% of Korean adolescents, especially those with low socioeconomic status or poor academic achievement, were involved in bullying, either as bullies or as victims [8
], suggesting that unjust treatment towards colleagues is rather ubiquitous among Korean adolescents. Adolescents are not the only subjects of unfair treatment; the Korean Working Conditions Survey, a nationwide survey conducted to evaluate the working conditions and health status of Korean workers, reported that 7.2% of workers had experienced unfair treatment at their workplace over the past 12 months [10
A number of previous studies have also indicated that the negative health effects of discrimination could be moderated by social support [4
]. However, effect modification by social support might be different in Asian populations due to cultural differences [12
]. Additionally, evidences have suggested that there are gender differences in social support [13
]. In this study, we examined the effects of discrimination on mental health in Korean general population and effect modification by social support to determine whether the results from previous studies could also be applied to the Korean population. Additionally, we attempted to investigate gender differences in social support by stratifying the study population according to gender and estimating the effect modification by social support in each gender group.
Perceived discrimination was positively associated with depressive symptoms in Korean young adults, and the association was stronger if participants received lower social support. Such results indicate that social support could moderate the negative health effects of perceived discrimination.
However, the health effects of discrimination and social support varied by gender. The association between discrimination and depressive symptoms was stronger in men, indicating that men are more vulnerable to discrimination than women. The adjusted R2 for the model adjusted for age, household income, and BMI (model A, Table 2
) also presented stronger model fit in man participants (men: 0.554; women: 0.151), and a stronger influence of discrimination on depressive symptoms in men. In contrast, the effect modification by social support was stronger in women. Differences in the regression coefficients of social support, changes in the adjusted R2
value after adjusting for the MSPSS scores (men: 0.554→0.558; women: 0.151→ 0.270) (Table 2
), and the results of the stratified analyses suggested that the effect modification by social support could be beneficial in both genders, but more so in women.
Few studies have tested the health effects of discrimination in Korean population, and most such studies have primarily focused on elderly populations [28
]. However, previous studies have shown that young Korean adults with low socioeconomic status or poor academic achievements could experience discrimination [8
]. To address this knowledge gap, we investigated the effects of discrimination on depression and moderation by social support in Korean young adults. Additionally, we explored gender differences in the impacts of discrimination and social support in the general population.
Our results suggest that the association between perceived discrimination and mental health is strong in Korean young adults, consistent with previous studies conducted in various ethnic groups [2
]. As the participants of our study were ethnic non-minority Koreans, most of them rarely experienced discrimination, and they reported a low degree of depressive symptoms. However, some of them reported a higher level of perceived discrimination and depressive symptoms than other participants. The regression coefficient of perceived discrimination on depression (β=0.736) suggests that non-minority individuals are not “safe” from discrimination and its negative effects on mental health, even though their baseline levels of depression and perceived discrimination are relatively low.
Since there could be cultural differences in the health effects of discrimination and social support [12
], results from Western populations cannot be directly applied to Asian populations with different cultural backgrounds. The ethnic and cultural homogeneity of the JS Cohort population could be helpful for understanding the health effects of discrimination and social support among Asian populations with high ethnic homogeneity.
Our results imply that the impact of discrimination on mental health is larger in men. A post-hoc analysis revealed a significant interaction between gender and discrimination (men as reference group, β=-0.574, p
<0.001). A similar study on immigrants implied that Iranian and Korean men are more vulnerable to discrimination-related depressive symptoms than their woman counterparts [17
]. Kim and Noh [17
] suggested that emotional reactions towards discrimination, such as anger and sadness, are more intense in Korean men immigrants, resulting in worse mental health effects. Furthermore, differences in the frequency and intensity of discrimination causes differences in resilience [30
]. In our study, woman participants reported a higher level of perceived discrimination, so it could be hypothesized that they developed resilience towards discrimination.
It is also notable that among Irish, Ethiopian, and Vietnamese immigrants, women were found to be more vulnerable to discrimination, unlike Korean and Iranian immigrants [30
]. According to Cokley et al. [31
], differences in coping mechanisms towards discrimination result in different health effects. This implies that results from different ethnic groups could not be directly applied to the Korean population, and that more research on the Korean population is needed to understand the role of discrimination in health.
The analysis presented in this study indicates that the association between perceived discrimination and depressive symptoms could be moderated by social support, implying that social support has a protective effect against discrimination. Interpersonal influences on emotional regulation are a mechanism through which social support acts on depressive symptomatology [32
]. Social support provides an interpersonal level of cognitive and emotional regulation, preventing depressive symptoms from developing further and diminishing former symptoms through cognitive changes and attentional deployment [32
]. Our results suggest that social support could moderate the negative health effects of discrimination, and providing social support could be a measure to prevent depression in non-minority individuals.
In our study, women received greater health benefits from social support than men. It has been consistently suggested that the health effects of social support are more beneficial in women [22
], since women have evolved to adapt befriending as a major mechanism to fight against stress [33
], which allows them to utilize social support to reduce stress and reobtain emotional regulation [32
]. Several previous studies have shown gender differences in social support [29
], supporting the implications of this study.
Support from friends was the most important domain in men, while family support was the most influential factor in women. According to Chopik [34
], friendship becomes more important from the perspective of health and welfare as we age, but this does not explain why family support was the most influential factor in women. Since women are influenced more by family support [35
], it could be postulated that the importance of support from friends grows earlier in men, becoming the most influential domain of social support in men.
Interestingly, BMI was positively associated with depressive symptoms in men, especially in those with low social support. The perception on ideal body image and its association with depression is highly culture-dependent; previous studies that analyzed body image in university students from 22 countries found that Asian young adults tended to overestimate their body shape, indicating that a lean body is perceived as ideal among Asian young adults [36
]. Kim [37
] suggested that body dissatisfaction is linked to suicidal ideation, and that social relations partially mediate this association. The results of our study are consistent with those of previous research [36
], and it suggests that overweight/obese individuals are prone to be dissatisfied with their body shape, resulting in depression. Further studies on the ideal body shape and its association with depression in Korean young adults should be conducted to obtain a more comprehensive understanding.
We are aware of several limitations of our study. Since this is a cross-sectional study, we cannot infer causality from its results. To complement this limitation, follow-up evaluations for psychological traits are currently underway. With longitudinal data, it will become possible to infer causality in further studies by establishing a temporal relationship between discrimination and depressive symptoms.
Generalization of our results may be challenging due to rural nature of the JS Cohort. A previous study conducted in China suggested that urban-born adolescents had better mental health and received higher social support [38
], but the opposite was true in a Korean study [39
]. Although the associations between urbanicity and psychosocial factors should be further investigated, the health effects of discrimination and social support might vary by urbanicity. Additionally, the relatively high socioeconomic status of our participants could affect psychosocial factors and their interactions, further hindering the generalizability of our findings [8
]. A nationwide study with national-level psychosocial indicators could provide a more comprehensive understanding of the health role of discrimination and social support. However, this demographic characteristic could yield advantages as well; the participants were relatively homogeneous and were mostly free from comorbidities, so confounding effects attributable to comorbidities were attenuated.
A significant proportion of participants were excluded because they did not complete the psychological examination. Although the baseline characteristics of the participants included in and excluded from this study were not significantly different, this might also be a source of bias.
Covariates measured in the first wave were utilized as surrogate variables to represent the current status of participants. Although the demographic variables included in this analysis are relatively non-time-dependent, differences between the first and third waves might have diminished the representativeness of the model. To minimize this concern, we excluded highly time-dependent lifestyle variables from our regression model.
Lastly, our measures of depressive symptoms were based on self-reported questionnaires, so reporting bias could have been present. For instance, depressed participants might have underestimated the social support they received, potentially resulting in a consequent overestimation of the association. However, we found a consistent direction of the association in the participants with high levels of social support, so the possibility of reporting bias is unlikely to alter the direction of the association.
Despite these limitations, this study could shed light on the role of discrimination and social support in the mental health of the Korean population. Although further studies are required to understand the health impacts of discrimination more accurately, we detected negative health impacts of discrimination in a Korean non-minority population. We also found that social support could be beneficial for community members experiencing discrimination, and that reactions towards discrimination and social support could vary by gender. Mental healthcare providers and community members should be aware of the negative health effects of discrimination, especially for members without sufficient social support.