The effect of five day dosing with THCV on THC-induced cognitive, psychological and physiological effects in healthy male human volunteers: A placebo-controlled, double-blind, crossover pilot trial

Summary & key facts

This small, placebo-controlled crossover trial gave 10 healthy men 10 mg oral THCV daily for five days, then 1 mg intravenous THC on day five. THCV was well tolerated and participants could not tell it from placebo. Under THCV, THC caused less increase in heart rate, felt subjectively weaker for 9 of 10 people, and the usual THC-related drop in delayed verbal recall was not seen. However, THCV plus THC increased memory intrusions. The authors warn the results are preliminary because the sample was small and the THC dose may not have produced typical psychosis-like or memory-impairing effects.

Key facts:

• Ten male participants who had used cannabis fewer than 25 times took part in a double-blind, placebo-controlled, crossover pilot trial.
• Participants received 10 mg oral pure THCV or placebo once daily for five days, and on day five they were given 1 mg intravenous THC.
• THCV was reported as well tolerated and subjectively indistinguishable from placebo by participants.
• THC produced significant intoxicating effects but did not significantly increase psychotic symptoms, paranoia, or impair short-term memory in this study.
• Delayed verbal recall was impaired by THC only under the placebo condition (Z = -2.201, p = 0.028), suggesting a protective effect of THCV on this measure.
• THCV inhibited the THC-induced increase in heart rate (Z = -2.193, p = 0.028).
• Nine out of ten participants reported the THC dose felt subjectively weaker or less intense when they had taken THCV compared to placebo (χ2 = 6.4, p = 0.011).
• THCV combined with THC significantly increased memory intrusions (Z = -2.155, p = 0.031).
• The authors note these findings need cautious interpretation because of the small sample size and because the THC dose may not have caused the usual psychotomimetic and memory-impairing effects.

Abstract

In this first study of THC and THCV, THCV inhibited some of the well-known effects of THC, while potentiating others. These findings need to be interpreted with caution due to a small sample size and lack of THC-induced psychotomimetic and memory-impairing effect, probably owing to the choice of dose.

Topics

Cannabis and Cannabinoid Research Neuroscience and Neuropharmacology Research Neurotransmitter Receptor Influence on Behavior

Categories

Health Sciences Medicine Pharmacology

Tags

Adverse effect Alternative medicine Anesthesia Antagonist Cannabinoid Cannabinoid receptor Cannabis Crossover study Delta-9-tetrahydrocannabinol Dronabinol Internal medicine Medicine Pathology Pharmacology Placebo Psychiatry Psychology Receptor Rimonabant Tetrahydrocannabinol Tolerability

Substances

Cannabis