The psychosis proneness: psychosis persistence model as an explanation for the association between urbanicity and psychosis

Given the relatively high attributable risks associated with urbanicity it is crucially important to learn more on how this exposure impacts on population risk for schizophrenia. Further elucidation of the environmental influences that currently go under the name of "urbanicity" therefore is a crucial step in unravelling the etiology of schizophrenia. In order to make the step from association to cause, a plausible mechanism detailing the pathway from impact of exposure to onset of psychotic symptoms is needed. This paper outlines possible avenues and clues to the identification of possible mechanisms and pathways. The focus is on mechanisms of gene-environment interaction in the context of both functional genetic polymorphisms and epigenetic variation.