1 Cincinnati Children's Hospital Medical Center Division, Developmental and Behavioral Pediatrics Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MCL 4002, Cincinnati, OH 45229, USA. Electronic address: ryan.adams@cchmc.org.
2 University of Nebraska at Omaha, Arts & Sciences Hall 418-C, 6001 Dodge St. Omaha, NE 68106, USA.
3 Concordia University, Department of Psychology, Center for Research in Human Development, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.

Objective: Previous research has identified a link between peer victimization and depressive symptoms during adolescence. The goal of the current study is to examine the possible indirect effects of HPA axis dysregulation in the link between adolescent peer victimization and depressive symptoms.

Method: A total of 113 boys (n = 61) and girls (n = 52) participants from grade 5 (M age = 10.31 years) and grade 6 (M age = 11.33 years) who were predominantly European-Canadian completed self-report measures of peer victimization and depressed affect as well as, measures of salivary cortisol and self-reports of negative experiences collected in conjunction with one another five times per day over the course of four school days.

Results: Multi-level structural equation modeling found that peer victimization was indirectly associated with depressive symptoms via blunted cortisol reactivity (i.e. increases in cortisol in response to a negative event) but only at high rates of chronic peer victimization.

Conclusion: The findings suggest that future studies should focus on HPA axis dysregulation for better understand the development, as well as the stability of depression over time and that interventions targeting peer victimization may want to put a special focus on those who are chronically experiencing peer victimization over time.