Depression is a major global mental health issue shaped by cultural, demographic, and occupational factors. This study compares predictors of depression across student and worker populations using datasets from India, Malaysia, and China. The India dataset was split into student and worker groups, while the Malaysia dataset includes only students and the China (CHARLS) dataset includes only workers. After harmonizing variables, we applied logistic regression, random forest, and causal forest models to identify key predictors and subgroup-specific effects, and conducted causal mediation analysis (CMA) to assess whether variables operate through intermediaries such as perceived pressure. Among students, pressure, age, workload, financial stress, mental health history, and satisfaction were significant predictors; similar factors emerged for workers. Notably, age showed opposite effects across groups: younger students were more likely to experience depression, whereas older workers showed higher risk. Model performance showed moderate internal accuracy but weaker external generalizability across countries, with random forest outperforming logistic regression. Causal forest results indicated limited heterogeneity in the effect of pressure, while CMA showed that pressure does not mediate the effect of age but operates more directly, and satisfaction influences depression partly through pressure. Overall, pressure consistently emerged as the strongest predictor, suggesting that interventions targeting academic and occupational stress may help reduce depressive symptoms.

翻译：抑郁是一种受文化、人口和职业因素影响的主要全球性心理健康问题。本研究利用来自印度、马来西亚和中国的数据集，比较了学生与工作者群体中抑郁的预测因素。印度数据集被划分为学生组与工作组，马来西亚数据集仅包含学生，中国（CHARLS）数据集仅包含工作者。在统一变量后，我们应用逻辑回归、随机森林和因果森林模型以识别关键预测因素及亚组特异性效应，并进行了因果中介分析（CMA）以评估变量是否通过感知压力等中介变量发挥作用。在学生群体中，压力、年龄、工作负荷、财务压力、心理健康史和满意度是显著的预测因素；工作者群体中也出现了类似因素。值得注意的是，年龄在两组中呈现相反效应：较年轻的学生更可能经历抑郁，而年长的工作者则表现出更高的风险。模型性能显示内部准确性中等，但跨国外部泛化能力较弱，其中随机森林的表现优于逻辑回归。因果森林结果表明压力的效应异质性有限，而CMA显示压力并未中介年龄的效应，而是更直接地发挥作用，同时满意度部分通过压力影响抑郁。总体而言，压力始终作为最强的预测因素出现，这表明针对学业与职业压力的干预措施可能有助于减轻抑郁症状。