Abnormalities in monetary and other non-drug reward processing in drug addiction

Adaptations of the reward circuit to intermittent and chronic supraphysiological stimulation by drugs increase reward thresholds. As a consequence, response to nondrug reinforcers in individuals with chronic drug use or addiction, may be decreased. Clinical symptoms include anhedonia and compulsive drug use, at the expense of the attainment of other rewarding experiences and despite detrimental consequences to the individual's functioning. While most addiction studies focus on the increased valuation of drug reward and drug-related cues, this chapter instead reviews the behavioural and neurobiological evidence for decreased valuation of non-drug reinforcers and cues.