Kebir O, et al. - The current study was expected to explore whether ABCB1 C3435T (rs1045642) polymorphism could modulate Δ9-Tetrahydrocannabinol (THC) blood levels in a sample of heavy cannabis users. The findings from the present study suggested that ABCB1 C3435T polymorphism could modulate serum THC levels in chronic heavy cannabis users. The exact mechanisms and roles that this could play in cannabis dependence genesis and evolution remained to be clarified. These outcomes should be controlled in a replication study using a larger population.

Methods

• Participants were thirty-nine Caucasian people, recruited in two French addictology centres, with isolated cannabis dependence and heavy use (defined as ≥ 7 joints per week).
• Each experienced clinical evaluation, cannabis blood metabolite dosage (THC, 11-OH-THC, and THC-COOH) and genotyping of ABCB1 C3435T polymorphism.

Results

• Average cannabis use was 21 joints per week (median 12; range 7 – 80) in this population (males: 74.4%, average age 29.5 +/- 9).
• Findings revealed that T carriers (TT/CT) had significantly lower plasma THC levels (ng/ml) versus non T carriers (8 vs 15.70, signficant), controlling for level of weekly use, 11-OH-THC and THC-COOH levels.