Positive and negative social support and depressive symptoms according to economic status among adults in Korea: cross-sectional results from the Health Examinees-Gem Study

OBJECTIVES: The interaction between positive and negative social support as well as each domain of social support and income on depressive symptom has not been much explored. We aimed to examine the associations of positive and negative social support with the risk of depressive symptoms among urban-dwelling adults in Korea, focusing on those interaction effects. DESIGN: We used the first wave of a large-scale cohort study called The Health Examinees-Gem Study. Positive and negative support scores ranged between 0 and 6; the variables were then categorised into low, medium, and high groups. A two-level random intercept linear regression model was used, where the first level is individual and the second is the community. We further tested for interactions between each domain of social supports and household income. SETTING: A survey conducted at 38 health examination centres and training hospitals in major Korean cities and metropolitan areas during 2009–2010. PARTICIPANTS: 21 208 adult men and women aged between 40 and 69 in Korea (mean age: 52.6, SD: 8.0). OUTCOME MEASURES: Depressive symptoms score measured by Epidemiologic Studies-Depression Scale, with scores ranging from 0 to 60. RESULTS: Level of positive and negative social support showed a negative and positive association with depressive symptom score with statistical significance at p<0.05, respectively. When the interaction terms among household income and social supports were examined, a negative association between level of positive social support and depressive symptom score was more pronounced as income was lower and level of negative social support was higher. Similarly, positive association between level of negative social support and depressive symptom score was more pronounced as income was lower and level of positive social support was lower. CONCLUSIONS: Our findings suggest that strategies for encouraging positive social support and discouraging negative social support for disadvantaged individuals might be effective in reducing depression in Korea.