DOPAMINE LIGANDS AND THE STIMULUS EFFECTS OF AMPHETAMINE - ANIMAL-MODELS VERSUS HUMAN LABORATORY DATA

Studies with laboratory animals have consistently demonstrated a role for dopamine in mediating the discriminative stimulus (i.e., interocep tive) effects of amphetamine, For example, D-2 dopamine agonists mimic the discriminative stimulus effects of amphetamine and D-1 and D-2 do pamine antagonist generally block them. The discriminative stimulus ef fects of drugs in animals are believed to parallel their subjective ef fects in humans. Therefore, it is often assumed that dopamine plays a role in amphetamine-induced subjective effects in humans and it would be reasonable to expect that dopamine antagonists would block the subj ective effects of amphetamine. Few studies have tested this hypothesis directly, and those that have have yielded inconsistent results. This paper will review data regarding the effects of dopamine agonists and antagonists on the discriminative stimulus effects of amphetamine in animals and its subjective effects in humans, Possible explanations fo r the discrepancies between animal and human data will be discussed, a nd classical assumptions underlying the use of animal models of drug e ffects will be examined.