Mental disorders like schizophrenia and autism put a heavy load on today’s societies, creating a steady call for revealing underlying disease mechanisms and the development of effective treatments. The etiology of major psychiatric illnesses is complex involving gene by environment susceptibility factors. Hence, a deeper understanding is needed of how cortical neurodevelopmental deficiencies can arise from such gene-environment interactions. The convergence of genetic and environmental risk factors is a recent field of research. It is now clear that disease, infection and stress factors may disrupt the normal function of neurodevelopmental genes. Here, the transcriptional repressor Zbtb20, which we and others have shown is a master regulator of hippocampal neurodevelopment, deserves special interest. We study the possibility that environmental factors such as steroid hormones, cytokines and antipsychotics mediate their effects on hippocampal neurodevelopment through deregulation of the Zbtb20 gene. A short presentation of the status of this work will shown.