Mechanisms of reward circuit dysfunction in psychiatric illness: prefrontal-striatal interactions.

The brain's "reward circuit" has been widely implicated in the pathophysiology of mental illness. Although there has been significant progress in identifying the functional characteristics of individual nodes within the circuit and linking dysfunction of these brain areas to various forms of psychopathology, there remains a substantial gap in understanding how the nodes of the circuit interact with one another, and how the growing neurobiological knowledge may be applied to improve psychiatric patient care. In this article, we summarize what is currently known about the functions and interactions of two key nodes of this circuit-the ventral striatum and the ventromedial prefrontal/orbital frontal cortex-in relation to mental illness.