The aim of the study is to investigate the relationship between peers’ private tutoring and an individual student’s depressive symptoms. Potential mechanisms that underlie this link were also explored.

Data are from the Gyeonggi Education Panel Study of 7th and 10th graders in South Korea. The present study exploited quasi-experimental variation generated from random assignment of students to classes within schools to examine whether having peers who receive private tutoring is associated with students’ self-reported depressive symptoms. The following mechanism variables were explored: hours spent doing leisure/hobby activities, test-related stress, hours spent playing with friends, and friend attachment.

The proportion of classmates who receive private tutoring was associated with an increase in students’ depressive symptoms (b = 0.326, p < .05), even after adjusting for individual- and peer-level covariates as well as school fixed effects. Results showed that exposure to a higher proportion of classmates who receive private tutoring leads to a decrease in hours spent engaging in leisure/hobby activities and an increase in test-related stress. Sobel-Goodman mediation tests suggested that test-related stress explains about 20% of the association between peers’ private tutoring and students’ depressive symptoms.

As more peers receive private tutoring, academic competition intensifies among students in East Asian and Southeast Asian countries. The findings of this study suggest that emotional pressure and anxiety generated by such environments threaten the mental health of adolescents. Policymakers may consider creating school-based interventions that foster a culture of cooperation, not competition.