During part of the past century any reference to genetics as cause for psychiatric disorders was vetoed, favouring explanations based on the environment as pathogen. Later and as a backlash, science seemed to bet on the sufficiency of the genetic level to understand pathology. Currently, in keeping with the consolidation of the neuroscientific paradigm, a higher level of complexity has been achieved and has rendered new models, such as gene-environment interaction and correlation, which allow for a more rigorous understanding of how the human phenotype displays itself in the world. Profound transformations in the field of mental health can be foreseen as a result of the new paradigm.