Reward Processing and Depressive Subtypes: Identifying Neural Biotypes

Deficits in motivation and pleasure are common in depression, and thought to be caused by alterations in the ways in which the brain anticipates, evaluates, and adaptively uses reward-related information. However, reward processing is a complex, multi-circuit phenomenon, and the precise neural mechanisms that contribute to the absence or reduction of pleasure and motivation are not well understood. Variation in the clinical presentation of depression has long been a rule rather than an exception, including individual variation in symptoms, severity, and treatment response. This heterogeneity complicates understanding of depression and thwarts progress toward disease classification and treatment planning. Discovery of depression-specific biomarkers that account for neurobiological variation that presumably underlies distinct clinical manifestations is critical to this larger effort.