Abstract
Background: Loneliness is a public health concern. Despite the increasing attention paid to loneliness globally, knowledge regarding the condition in Korea is scarce. This study aims to examine the correlates of loneliness and social isolation among Korean adults. Methods: This cross-sectional study used a nationally representative sample of adults aged 30 years and older from the 2021 National Mental Health Survey of Korea (N = 4696). The survey used the six-item loneliness and social isolation scale (LSIS-6) to assess loneliness and social isolation between June and August, 2021. Two ordinary least squares regression models were conducted. Model 1 included socio-demographic variables as correlates of loneliness and social isolation. Model 2 added a range of mental health conditions, such as depressive disorder, anxiety disorder, alcohol-use disorder, nicotine-use disorders, and physical inactivity. Mental health was measured in relation to whether the participant had experienced each disorder in his/her lifetime. Results: A total of 34.4% of participants reported that they felt lonely at least occasionally. After all adjustments, the experience of mental health conditions was associated with an increase in the LSIS-6 score (B = 2.32 for depressive disorder, B = 0.59 for anxiety disorder, B = 0.36 for both alcohol-use disorder and nicotine-use disorder; p < 0.01). In addition, greater loneliness and social isolation were associated with male gender, older age, a lower educational level, non-married status, a lower household income, having a smaller number of children, having a greater number of chronic conditions, and taking less frequent walks per week. Conclusions: In conclusion, loneliness is prevalent among Korean adults. Loneliness and social isolation correlated significantly with socio-demographic characteristics and the experience of mental health conditions.