Chunk #27 — 2. Neural substrates for the negative emotional state associated with addiction — 2.1. Within-system neuroadaptations that contribute to the negative emotional state component of compulsivity
Psychostimulant withdrawal in humans is associated with fatigue, decreased mood, and psychomotor retardation and in animals is associated with decreased motivation to work for natural rewards (Barr and Phillips, 1999) and decreased locomotor activity (Pulvirenti and Koob, 1993), behavioral effects that may involve decreased dopaminergic function. Animals during amphetamine withdrawal show decreased responding on a progressive-ratio schedule for a sweet solution, and this decreased responding was reversed by the dopamine partial agonist terguride (Orsini et al., 2001), suggesting that low dopamine tone contributes to the motivational deficits associated with psychostimulant withdrawal.
