The Effect of Peers’ Genetic Predisposition to Depression on Own Mental Health


Jeong, Yeongmi (2023). The Effect of Peers' Genetic Predisposition to Depression on Own Mental Health. 2023 Allied Social Sciences Associations (ASSA) Annual Meeting. New Orleans, LA.


The goal of this research is to examine whether peers’ genetic predisposition for depression affects one’s own mental health in the short- and long-run by considering same-gender grademates as peers. There has been growing concern about adolescent depression. Adolescents with depression are about three times more likely to be depressed in adulthood compared to non-depressed adolescents (Johnson et al., 2018). Therefore, understanding the factors that affect adolescent and adult depression is key for preventing and treating depression. Since peers have particularly strong impacts on each other during adolescence (Brown and Larson, 2009), peers’ mental health may be an important determinant of own mental health. In this study, I use data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), which follows a nationally representative sample of US adolescents starting in the 1994-95 school year. The genetic data in Add Health includes the polygenic risk score for major depressive disorder (hereafter, MDD score), a composite measure of genetic markers that are correlated with MDD. A higher MDD score means a higher genetic risk for depression. The individual MDD score is used to construct same-gender grademates’ average MDD score, which is the main explanatory variable of interest. I find that an increase in same-gender grademates’ average MDD score is significantly associated with an increase in the probability of being depressed in adulthood for both males and females, with weaker effects on adolescent own depression. I explore the mechanisms underlying the relationship, including substance use, educational performance and attainment, and labor market choices.


Reference Type

Conference proceeding

Book Title

2023 Allied Social Sciences Associations (ASSA) Annual Meeting


Jeong, Yeongmi

Year Published


City of Publication

New Orleans, LA

Reference ID