Effects of setting on the subjective and behavioral effects of d-amphetamine in humans

The effects of setting on the subjective and behavioral effects of 20 mg oral d-amphetamine were studied in eight healthy volunteers. A within-subjects design was used in which subjects ingested either amphetamine or placebo capsules in either an inpatient (isolated laboratory room) or an outpatient (normal daily environment) setting. The order of the four experimental conditions was randomized across subjects. Subjective drug effects were assessed using the Profile of Mood States, the Addiction Research Center Inventory, a Visual Analogue Scale, and a Drug Effects/Liking questionnaire, completed prior to and 1, 3, and 6 h after capsule ingestion. In addition, an End-of-Session questionnaire measuring overall drug liking and drug identification was completed at the 6-h timepoint. Subjects wore wrist monitors to record their physical activity levels during the 6-h postingestion period. Amphetamine produced typical stimulant-like subjective effects such as elation, euphoria, and friendliness, but the setting neither quantitatively nor qualitatively altered the drug response.