Hallucinogenic drugs attenuate the subjective response to alcohol in humans.

This study investigated possible interactions between alcohol and hallucinogens in 22 lysergic acid diethylamide (LSD) and/or psilocybin users through retrospective structured interviews. Of those who had used LSD with alcohol, 86;7 per cent reported a complete blockade of subjective alcohol effects, while the remaining cases reported a diminished response. In addition, 60 per cent of respondents who had used alcohol and psilocybin together reported a partial antagonism of subjective alcohol effects.T-test analyses revealed that LSD's antagonism of alcohol effects were significantly greater than those associated with psilocybin. It is proposed that LSD's effect on alcohol intoxication may involve interactions with various serotonergic and/or dopaminergic receptor systems. Copyright 2000 John Wiley & Sons, Ltd.