Chronic family stress interacts with 5-HTTLPR to predict prospective depressive symptoms among youth

Background: Previous research, predominantly with adults, has shown that the serotonin transporter gene (5‐HTTLPR) interacts with stress (G × E) to predict depressive symptoms; however, few G × E studies have been conducted with youth using rigorous methods, particularly a prospective design and contextual interview to assess stress. This study examined the interaction between 5‐HTTLPR and stress, both chronic and episodic, to predict longitudinal change in depressive symptoms among children and adolescents. Methods: A general community sample of youth (N = 200; 57% girls; mean age: 12.09 years old) was genotyped for 5‐HTTLPR (rs 25531) at baseline. They were interviewed via contextual stress procedures to ascertain chronic family stress and episodic stressors and completed depressive symptoms questionnaires at baseline and 6 months later. Results: A significant G × E showed that chronic family stress predicted prospective increases in depressive symptoms over 6 months among youth possessing the high‐risk S allele. This G × E was not found for episodic stressors occurring in the last 6 months. There was no moderation by sex or pubertal status. Conclusions: These findings advance knowledge on G × E effects in depression among youth. This is the first study to show that chronic family stress, but not episodic stressors, when ascertained by rigorous stress interview, interacts with 5‐HTTLPR to prospectively predict depressive symptoms among children and adolescents. Depression and Anxiety, 2011. © 2011 Wiley Periodicals, Inc.