Anhedonia in Depression: Neurobiological and Genetic Aspects

Anhedonia is a pathogenetically important clinical phenotype and a potential endophenotype for depressive symptoms with very high contributions from biological and genetic factors. The neurobiological mechanisms of anhedonia consist of impairments to the functioning of the brain “reward” system, which has been confirmed by a significant number of neuroimaging, genetic, and experimental studies. Anhedonia is transnosological in nature and is a complex phenomenon; its correct assessment in the context of one or another investigation paradigm is important. The optimum approach is to form a set of mutually supplementing investigation strategies assessing the most important facets of anhedonia, regardless of the relationship with the nosological form of the illness, in the framework of a single study using various methods to seek appropriate biomarkers for the severity of anhedonia (genetic, neuroimaging, biochemical). High-quality organization of studies of this type based on correct evidence-based medicine methodology should produce valuable systems of biomarkers in the near future, which when validated on independent cohorts will be useful for personalizing the diagnosis and treatment of depression.