The neural circuitry of reward and its relevance to psychiatric disorders.

Scientific interest in how the brain processes reward has burgeoned during the past 50 years since the discovery that rats will do tasks such as pressing a lever to obtain electrical stimulation of the brain. This interest was additionally encouraged by the observation of an association between reward and dopamine activity in the mesocorticolimbic system. In this article, we will discuss the complex nature of reward processing and recent animal studies and human functional neuroimaging studies to elucidate the current understanding of the neural substrates of reward processing and its components. Lastly, we will review recent theoretical and empirical work investigating the role of brain reward circuitry in several psychiatric disorders, including substance use disorders, schizophrenia, pathologic gambling, major depressive disorder, and attention-deficit/hyperactivity disorder.