Anhedonia revisited: is there a role for dopamine-targeting drugs for depression?

It is 16 years since we reviewed anhedonia in depression. Since then, there have been important developments in the study of anhedonia, mainly using the new techniques that neuroimaging made available, which provide very interesting new insights. It is becoming increasingly apparent that anhedonia, with psychomotor retardation, defines a dimension in depressive disorder that seems to be distinct from a dimension encompassing mood plus somatic symptoms. These dimensions can coexist, but may also be present separately. The first appears associated with disturbances (under-functioning) in dopamine function; the other appears to be related to a similar under-functioning in the serotonin system. Furthermore, anhedonia itself increasingly appears to be a composite symptom, consisting of at least two dimensions (i.e. a motivational/appetitive and a consummatory one). Depression appears to be characteristically linked more to the first one, in contrast to what was originally thought. We discuss the significance of the above in the evolving treatment of depression and the potential use of dopamine-targeting drugs.