Gene x Environment mouse models for mood disorders.

Much of the impact of genes on mood disorders likely depends on interactions between genes and the environment. Recent studies demonstrating an interaction between specific genes and life stressful events (early and/or adult) in the modulation of several mood disorders (e.g., serotonin transporter and brain-derived neurotrophic factor genes) have compelled researchers to incorporate information about adverse environmental experiences into the study of genetic risk factors; these same gene-by-environment (G×E) interactions have been identified in mouse models. Notably, G×E not yet described in humans (e.g., serotonin 1A receptor gene) have been uncovered, providing helpful indications to discover similar interactions in humans. Accurate knowledge of the modality of expression of gene-by-stress interaction may help design prevention protocols aimed at identifying susceptibility to mood disorders on the basis of genetic predisposition and exposure to environmental stressful conditions, thus providing patients with appropriate pharmacological and psychological support.