Anhedonia

Anhedonia is a diverse array of deficits in hedonic function, understood in current research not simply as an inability to feel pleasure but as reduced motivation to pursue rewards, diminished anticipatory and consummatory pleasure, and impaired reinforcement learning. The DSM-5 lists it as a diagnostic component of depressive disorders, substance-related disorders, psychotic disorders and certain personality disorders, defined as a reduced ability to experience pleasure or a diminished interest in previously enjoyable activities. The term derives from the Greek an- (without) and hedone (pleasure); it was coined by the French psychologist Theodule-Armand Ribot and later used by psychiatrists Paul Eugen Bleuler and Emil Kraepelin, who treated it as a core symptom of schizophrenia. It is classified within psychiatry.