The human brain does not develop in a vacuum according to a set of predetermined blueprints-it is involved in a dynamic interplay with the environment that influences gene expression and ultimately structure and function. Some cortical regions, such as the prefrontal cortex (PFC) undergo structural changes throughout the adolescent period and into early adulthood, making their structure and functions particularly interesting to study with respect to gene-environment interactions. Repeated exposure to stress is a predisposing factor in the emergence of various mental illnesses, such as anxiety...