Reinforcing effects of triazolam in sedative abusers: correlation of drug liking and self-administration measures

Six male subjects with histories of sedative abuse were allowed to orally self-administer a maximum of 18 color-coded triazolam and placebo capsules during daily 3-h sessions. The schedule of reinforcement was a signaled fixed-interval 10-min schedule in which triazolam and placebo were concurrently available as mutually exclusive choices. Triazolam was shown to be a reinforcer in four of the six subjects. The two subjects who did not self-administer triazolam in preference to placebo also had lesser histories of drug dependence. Self-administration of triazolam (0.125 or 0.25 mg per capsule) was generally stable over 7-10 days. Manipulations of triazolam dose (0.0312-0.25 mg) per capsule in two subjects showed that the number of capsules self-administered was inversely related to capsule dose. Subject ratings of drug liking obtained from experimenter-administered doses of triazolam were correlated with self-administration behavior occurring 1-7 days later. Of the subject ratings, next day ratings obtained on the day after dosing resulted in significant correlations whereas same day ratings obtained while subjects were under the influence of triazolam did not. These results have important implications for abuse liability prediction and suggest that next day ratings have greater predictive validity than measures collected while subjects are under the influence of benzodiazepines.