 The study of reward in depression is limited by heterogeniety in the definition and conceptualizations of reward and anhedonia.Anhedonia is broadly defined as a reduced ability to feel pleasure, but questionnaires and clinical assessments rarely distinguish between motivational "wanting" and consummatory "liking".While a number of studies suggest that depressed subjects rate positive stimuli less positively and as less arousing, a number of studies fail to find a difference.