Wanting and liking are separate, and anhedonia can break one without the other
Anhedonia was first described in 1896 as a lost capacity for pleasure. Researchers now split pleasure into parts: the anticipation that drives you toward a reward, and the enjoyment once you have it. In schizophrenia, strikingly, the enjoyment often survives while the anticipation falters.
The French psychologist Théodule-Armand Ribot coined the idea in 1896 as a reduced ability to feel pleasure. Modern research treats it as a family of reward deficits: weaker motivation, less anticipatory pleasure, called wanting, less pleasure in the moment, called liking, and problems learning from rewards. Whether learning is truly a separate strand remains unproven. Studies also find that what people report about their own pleasure can differ from what their behaviour shows. In PTSD the term overlaps with emotional numbing and flat affect, and scales for those correlate strongly with standard anhedonia measures.
In the DSM-5 it appears across depressive, substance-related, psychotic and personality disorders. About 70 percent of people with major depression experience it, and because it is a core symptom, someone can be diagnosed with depression even without feeling low. Telling lost interest from lost pleasure is tricky, since people naturally lose interest in what no longer pleases them. Many describe food losing its appeal, which may link it to the weight-loss criterion.
Schizophrenia offers the clearest case of wanting and liking coming apart. Patients recall fewer positive emotions overall, yet when actually given something rewarding they report as much pleasure as anyone, and brain scans usually show normal reward-system responses to simple rewards. The weak point is anticipation: emotional responses while awaiting a reward are consistently reduced. Learning difficulties show up only on explicit or complex tasks; implicit learning holds up fairly well.
The leading theory blames a breakdown in the brain's dopamine-based reward system. Implicated regions include the orbitofrontal cortex, striatum, amygdala, anterior cingulate cortex, hypothalamus and ventral tegmental area. Human imaging ties deficits in liking to the ventral striatum and medial prefrontal cortex, and deficits in wanting to the hippocampus and prefrontal areas. Animal work broadly agrees, except on the orbitofrontal cortex, a region that is hard to image because of where it sits.
Source: Anhedonia
