Both genetic factors and concomitant environmental exposures act on mental health, the effects of which can mutually modify each other in a complex way. The environment can in fact influence the way in which DNA is read and transcribed through chemical modifications, thus directly regulating the functional activation of genes (epigenetics). Epigenetics plays a fundamental role in the processes of brain plasticity.
When genetic effects are modulated by exogenous factors, such as lifestyles, opportunities exist for prevention and mental health promotion.
The Istituto Superiore di Sanità (ISS, the National Institute of Health in Italy) addresses the issue of gene-environment interactions in mental health both using experimental models and with a population approach, for example on samples of twins (estimation of the heritability of traits in different exposure categories ) and on birth cohorts in which the effects of interactions between the genome and environmental factors on neurobehavioral development are investigated.