Background: Past findings on gene-by-environment (G×E) effects on depression have been mixed, leading to a debate of the plausibility of such mechanisms and methodological considerations that warrant attention. A developmental systems perspective postulates that complex, multi-level G×E effects are likely contributors to depression. Methods: Participants from families experiencing low-income status at birth were followed over 28 years. Maltreatment was recorded prospectively using multiple means and sources. Depression was measured repeatedly using well-validated interviews in middle childhood, through adolescence, and into adulthood. Results: Findings support a G×E effect where the less efficient form of the promoter region of the serotonin transporter gene (5-HTTLPR) contributes to a vulnerability to depressogenic aspects of maltreatment in childhood and adolescence. The presence of less efficient forms of the 5-HTTLPR polymorphism and maltreatment together raised risk for depression. This G×E effect was present generally and also among those who reported clinical levels of depression at only one point in time. Limitations: This study used a low-income sample which limits generalizability to other populations. Sample size and rates of different forms of depression and depression at individual developmental stages supported general analyses, but limited the sorts of specific sub-analyses that were possible. Conclusions: These findings support the plausibility of G×E effects on depression during childhood, adolescence, and early adulthood, key periods for the development of depression. Ongoing debates about the presence of G×E effects would be well served by additional work that was theoretically informed and employed prospective, longitudinal methodologies with well-validated measures of key constructs.
Bibliographical noteFunding Information:
This research was supported by a National Institute of Mental Health (NIMH) grant to Byron Egeland (R01MH40864-09), by a grant from the Spunk Fund, Inc. to Dante Cicchetti, by a National Institute of Child Health and Human Development (NICHD) grant to W. Andrew Collins (R01HD054850), by predoctoral fellowships awarded to J.J. Cutuli from the Center for Neurobehavioral Development (CNBD), University of Minnesota and the National Institute of Mental Health (NIMH; 5T323MH015755), and by a predoctoral training grant awarded to K. Lee Raby from the National Institute of Mental Health (T32MH015755-33). All interpretations, recommendations, conclusions, and other points of view are those of the authors and do not necessarily reflect those of NIMH, NICHD, or CNBD.
- Child maltreatment
- Childhood, adolescence, and adulthood
- Gene-by-environment interaction