Abstract
BACKGROUND: Depression in middle-aged individuals is influenced by multiple factors; however, research focusing on this demographic remains limited. The social-ecological system framework explores how interactions among individual characteristics, social relationships, and environmental contexts contribute to health outcomes. This study aimed to assess the prevalence, core manifestations, and influencing factors of depression through a comprehensive model grounded in the social-ecological system. METHODS: Using data from the 2018 Chinese Labor Dynamic Survey, a total of 3,799 middle-aged individuals (mean age: 52.35 years; 53.75% female) were included. Depression was assessed using the Center for Epidemiological Studies Depression Scale, with a cut-off score of 36. We used a graphical gaussian model to identify the measurement network and core symptoms of midlife depression, and logistic regression to identify influencing factors. A social-ecological model of middle-aged depression was constructed through a Mixed Graphical Model. RESULTS: 23.74% of participants exhibited clinically significant depression. Feelings of disgust (Strength = 2.18, Expected Influence = 1.30) and incapacity (Strength = 1.29, Expected Influence = 1.57) emerged as the most central symptoms. Higher global strength (GS = 8.89, p < 0.001) of the network suggested stronger associations and mutual exacerbation of symptoms. Logistic regression showed that education, exercise, and subjective feeling were associated with depression risk (p < 0.05). The social-ecological system emphasized the importance of education (Strength = 2.50, Expected Influence = 2.50) and complex interaction between subjective and objective influencing factors. CONCLUSION: This study found middle-aged individuals had a high prevalence of depression, characterized by feelings of disgust and incapacity. Influencing factors spanned individual, social and environmental levels. These results emphasize the role of education in depressive individuals, providing guidance for potential future interventions.