This study investigates whether exposure to peer depression in adolescence affects own depression in adulthood. We find a significant long-term depression peer effect for females but not for males in a sample of U.S. adolescents who are followed into adulthood. An increase of one standard...

We provide first evidence that peer depression in adolescence affects own depression in adulthood. We use data from Add Health and an identification strategy that relies on within-school and across-cohort idiosyncratic variation in the share of own-gender peers who are depressed. We find a...