Abstract
Background. It is generally acknowledged that the vast majority of serious mental disorders have significant genetic contributions that manifest complex inheritance patterns. Despite this, few gene polymorphisms have been unambiguously identified as risk factors for behavioral illness and the mechanisms through which these select polymorphisms affect human behavior is completely unclear. One of the major reasons for this lack of progress is the phenomenon of gene-environment (GxE) interactions.
Methods. We review prior evidence of GxE interactions for major depressive disorder (MDD) in the Iowa Adoption Studies.
Results. The results demonstrate the usefulness of these cohorts to direct G effects for MDD.
Conclusions. We conclude that further use of the adoption paradigm will generate critical insight into the effects of candidate genes for a variety of complex human behavioral illnesses.
Notes
* p < 0.05; **p < 0.01, ***p < 0.001.