5-HT1A receptor blockade potentiates the subjective effects of DMT.

INTRODUCTION: -dimethyltryptamine (DMT). METHODS: In a double-blind, randomized, placebo-controlled within-subjects design, 12 (10 males, 2 females) experienced hallucinogen-using participants received a sub-hallucinogenic dose of intravenous DMT fumarate, 0.1 mg/kg, after pre-treatment with 30 mg oral racemic pindolol. Subjective effects were measured using the Hallucinogen Rating Scale. Blood pressure and mean arterial pressure also increased with pindolol pre-treatment at 2 minutes following DMT administration, but heart rate was not affected. CONCLUSIONS: receptor action in the mechanism of psychedelic-induced subjective effects.