EFFECTS OF EXPECTANCIES ON SUBJECTIVE RESPONSES TO ORAL DELTA(9)-TETRAHYDROCANNABINOL

The effects of expectancies on subjective responses to oral Delta(9)-t etrahydrocannabinol (Delta(9)-THC) were examined. Thirty-five regular marijuana users were assigned to one of two groups: one group was told that they may receive a cannabinoid or placebo and a second group was told that they may receive a drug from one of several classes of drug s (e.g., stimulant, sedative, antiemetic) or placebo. Regardless of th e group to which they were assigned, subjects received each of two ora l doses of Delta(9)-THC (7.5 and 15 mg) and placebo, one dose per sess ion, for a total of three sessions. Measures of subjective effects, in cluding visual analog scales and the Addiction Research Center Invento ry (ARCI), were administered at 0.5-h intervals throughout each sessio n. Consistent with previous research using other drugs, subjects in th e current experiment who expected to receive a cannabinoid reported gr eater pleasurable effects than subjects who did not have this expectan cy. The used in both recreational and clinical settings. results have implications for understanding the effects of cannabinoids when (C) 19 98 Elsevier Science Inc.