Triazolam discrimination by humans under a novel response procedure: effects of buspirone and lorazepam.
Six healthy human volunteers (ages 18 to 24) acquired a triazolam (0.32mg/70kg) vs placebo discrimination under a standard, two-response drug discrimination procedure. Dose-effect curves were then determined for triazolam (0.1-0.56mg/70kg), lorazepam (0.75-3.0mg/70kg) and buspirone (7.5-30mg/70kg) under a novel response procedure that provided a response alternative for drugs unlike triazolam or placebo (i.e. a novel-appropriate response). Triazolam dose-dependently increased triazolam-appropriate responding but did not occasion any novel-appropriate responding. Lorazepam dose-dependently increased triazolam-appropriate responding in four of six subjects, but at least one dose also occasioned novel-appropriate responding in three subjects. Buspirone dose-dependently increased novel-appropriate responding, although three of six subjects also made triazolam-appropriate responses following some dose(s). All three drugs comparably increased self-reported sedation. Self-reported effects did not differentiate triazolam from lorazepam whereas only buspirone increased "bad" self-reports, and did not increase "liking" and "good" self-reports. The results suggest that the novel response procedure enhanced the pharmacological selectivity of human benzodiazepine discrimination and may help interpret partial generalization under two-choice drug discrimination procedures. The results also add to the evidence of a close relationship between the discriminative stimulus and self-reported effects of drugs.
Department of Psychiatry, University of Vermont, Burlington, VT 05401, USA.
J.B.
JB
Kamien
W.K.
WK
Bickel
A.H.
AH
Oliveto
B.J.
BJ
Smith
S.T.
ST
Higgins
J.R.
JR
Hughes
G.J.
GJ
Badger