Impact of Psychoactive Drugs on Hypnotizability

Eleven adult male marihuana smokers who were pre-tested for hypnotic susceptibility were later tested for hypnotic susceptibility under four experimental conditions: (a) After smoking a cannabis cigarette containing 7.5 mg of tetrahydro cannabinol and receiving placebo IM injection; (b) After smoking a placebo cannibis cigarette and receiving 2 mg of haloperidol IM; (c) After a combination of both drugs; and (d) After placebo smoke and placebo injection. The drugs had no systematic impact on hypnotizability as measured by a modified version of the Harvard Group Scale of Hypnotizability.