Citation

Lile JA, Kelly TH, Hays LR. Drug Alcohol Depend. 2014; 143: 141-148.

Affiliation

Department of Psychiatry, University of Kentucky College of Medicine, 3470 Blazer Pkwy, Lexington, KY 40509-1810, USA; Department of Internal Medicine, University of Kentucky College of Medicine, 740 South Limestone St., J525 Kentucky Clinic, Lexington, KY 40536-0284, USA.

Copyright

(Copyright © 2014, Elsevier Publishing)

DOI

10.1016/j.drugalcdep.2014.07.016

PMID

25124305

Abstract

BACKGROUND: Our previous research suggested the involvement of γ-aminobutyric acid (GABA), in particular the GABAB receptor subtype, in the interoceptive effects of Δ(9)-tetrahydrocannabinol (Δ(9)-THC). The aim of the present study was to determine the potential involvement of the GABAA receptor subtype by assessing the separate and combined effects of the GABAA positive allosteric modulator diazepam and Δ(9)-THC using pharmacologically selective drug-discrimination procedures.

METHODS: Ten cannabis users learned to discriminate 30mg oral Δ(9)-THC from placebo and then received diazepam (5 and 10mg), Δ(9)-THC (5, 15 and 30mg) and placebo, alone and in combination. Self-report, task performance and physiological measures were also collected.

RESULTS: Δ(9)-THC functioned as a discriminative stimulus, produced subjective effects typically associated with cannabinoids (e.g., High, Stoned, Like Drug) and elevated heart rate. Diazepam alone impaired performance on psychomotor performance tasks and increased ratings on a limited number of self-report questionnaire items (e.g., Any Effect, Sedated), but did not substitute for the Δ(9)-THC discriminative stimulus or alter the Δ(9)-THC discrimination dose-response function. Similarly, diazepam had limited impact on the other behavioral effects of Δ(9)-THC.

CONCLUSIONS: These results suggest that the GABAA receptor subtype has minimal involvement in the interoceptive effects of Δ(9)-THC, and by extension cannabis, in humans.

Language: en