An experimental paradigm for studying the discriminative stimulus properties of drugs in humans

An experimental paradigm for studying the discriminative stimulus effects of drugs in human subjects is presented. The paradigm was tested by training subjects to discriminate 10 mg d-amphetamine from placebo. Subjects who successfully learned the discrimination were then tested with two lower doses of d-amphetamine and with 10 mg diazepam. The discriminative stimulus properties of d-amphetamine were dose-dependent, and in two of five subjects the d-amphetamine stimulus generalized to diazepam. The simplicity and versatility of the paradigm give it the potential for use in a wide variety of experimental and clinical situations.