Causes
Researchers theorize that anhedonia may result from the breakdown in the brain's reward system, involving the neurotransmitter dopamine. Studies by Paul Keedwell, MD, then of King's College, found that the brains of participants who were clinically depressed had to work harder to process rewarding experiences. While earlier research believed dopamine to be primarily involved in the subjective experience of pleasure, the last 20 years has seen a conceptual shift, such that dopamine is now believed to underlie various aspects of reward anticipation, learning, and motivation
Anhedonia is also a relatively common side effect of antidopaminergic neuroleptics or antipsychotic drugs.
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