Genetic susceptibility to family environment: BDNF Val66met and 5-HTTLPR influence depressive symptoms.

• Type of Material: Article
• Authors: Elizabeth D. Dalton, University of California; Constance L. Hammen, University of California; Jake M. Najman, University of Queensland; Patricia Brennan, Emory University
• Language: English
• Date: 2014
• Publisher: American Psychological Association
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2017 American Psychological Association.
• Final Published Version (URL): http://dx.doi.org/10.1037/fam0000032
• Title of Journal or Parent Work: Journal of Family Psychology
• ISSN: 0893-3200
• Volume: 28
• Issue: 6
• Start Page: 947
• End Page: 956
• Grant/Funding Information: This research was supported by National Institute of Mental Health R01 MH052239 to Brennan, Hammen, and Najman.
• Keywords: cumulative plasticity; depression; early family environment; differential susceptibility; 5-HTTLPR; val66met
• Research Categories: Psychology, Behavioral; Health Sciences, Public Health; Health Sciences, Mental Health

Abstract

Functional genetic polymorphisms associated with Brain-Derived Neurotrophic Factor (BDNF) and serotonin (5-HTTLPR) have demonstrated associations with depression in interaction with environmental stressors. In light of evidence for biological connections between BDNF and serotonin, it is prudent to consider genetic epistasis between variants in these genes in the development of depressive symptoms. The current study examined the effects of val66met, 5-HTTLPR, and family environment quality on youth depressive symptoms in adolescence and young adulthood in a longitudinal sample oversampled for maternal depression history. A differential susceptibility model was tested, comparing the effects of family environment on depression scores across different levels of a cumulative plasticity genotype, defined as presence of both, either, or neither plasticity alleles (defined here as val66met Met and 5-HTTLPR ‘S’). Cumulative plasticity genotype interacted with family environment quality to predict depression among males and females at age 15. After age 15, however, the interaction of cumulative plasticity genotype and early family environment quality was only predictive of depression among females. Results supported a differential susceptibility model at age 15, such that plasticity allele presence was associated with more or less depressive symptoms depending on valence of the family environment, and a diathesis-stress model of gene-environment interaction after age 15. These findings, although preliminary because of the small sample size, support prior results indicating interactive effects of 5-HTTLPR, val66met, and environmental stress, and suggest that family environment may have a stronger influence on genetically susceptible women than men.