Discriminative Stimulus Effects of Buspirone in Humans

Human Ss (N = 22) were trained to discriminate 15 mg buspirone (BS) from placebo. On the first 4 sessions, drugs were identified by letter code. During the next 7 sessions, capsules were not identified. Six hours later, Ss reported their identification. If Ss were correct on at least 5 sessions, a third phase began with 8 additional training sessions. During the other 8 sessions, Ss received test drugs. Four Ss failed to maintain the discrimination during this phase. The remaining 8 identified 5 mg BS, 200 mg meprobamate, 20 mg fluoxetine, and 10 mg d-amphetamine as placebo and 10 mg diazepam, 0.25 mg triazolam, and 75 mg tripelennamine as BS. Half identified 50 mg pentobarbital as BS. BS produced significant changes on several subjective effects measures typical of sedativelike drugs. The subjective effects of test drugs were largely correlated with drug identification.