Contrast Effect on Subjective Experience in Drug Experiments

Abstract

Contrast effects in an experiment involving no-drug, placebo, and seven drugs were postulated on the basis of Helson's adaptation level theory. For 250 male opiate addicts, it was expected and found that general subjective experiences peculiar to drugs were smaller for no-drug or placebo conditions when these conditions were administered after rather than before potent drugs such as morphine or LSD.