The authors present three major models for the joint effect of genes and
environment on liability to psychiatric illness: additive effects of
genotype and environment, genetic control of sensitivity to the
environment, and genetic control of exposure to the environment. Each model
is illustrated by several examples, including a quantitative one. The
authors attempt to demonstrate that genes and the environment can interact
in several interesting and potentially subtle ways, that these interactions
can be expressed in simple models from which clear empirical predictions
can be generated, and that elucidation of the etiology of psychiatric
disorders will require the consideration of both genetic and environmental
risk factors.Abstract Teaser