Archival ReportNeural Basis of Δ-9-Tetrahydrocannabinol and Cannabidiol: Effects During Response Inhibition
Section snippets
Design
A double-blind, placebo-controlled, pseudo-randomized, within-subject study was conducted over three sessions (placebo, THC, CBD). Each participant was scanned three times with a 1-month interval between scans. The order of drug administration across sessions was pseudo-randomized across subjects, such that equal numbers followed each drug sequence.
Participants
Fifteen healthy Caucasian right-handed men, aged 20 to 42 years (average 26.7 years, SD 5.7) completed the study by taking part in all three imaging
Task Performance
All participants performed the task with a high degree of accuracy. There were no significant differences for mean inhibition errors or mean reaction times between placebo, THC, and CBD treatments (Table 1), although left/right errors were more common (p < .05) following both THC and CBD than placebo (Table 1).
Physiologic Variables
Mean whole blood levels of THC at 1 and 2 hours after taking the drug were 3.9 (SD 7.3) ng/mL and 5.1 (SD 5.6) ng/mL, respectively. Mean whole blood level of CBD at the same time points
Discussion
In this study, we used fMRI to investigate how the two main psychoactive ingredients of cannabis (THC and CBD) modulate brain function during response inhibition. We employed a double-blind, placebo-controlled, repeated-measures within-subject design, measuring the BOLD response while subjects performed a Go/No-Go paradigm (52) following oral challenge with THC, CBD, or placebo. Consistent with our hypothesis, we found that THC attenuated activation in the right IFG and ACG. This effect was
References (76)
- et al.
Investigating the neurocognitive deficits associated with chronic drug misuse
Curr Opin Neurobiol
(2001) - et al.
Early-onset cannabis use and cognitive deficits: What is the nature of the association?
Drug Alcohol Depend
(2003) - et al.
Adverse effects of cannabis
Lancet
(1998) Reducing the harms caused by cannabis use: The policy debate in Australia
Drug Alcohol Depend
(2001)- et al.
Cognition and motor control as a function of Delta9-THC concentration in serum and oral fluid: Limits of impairment
Drug Alcohol Depend
(2006) - et al.
Drugs of abuse and the elicitation of human aggressive behavior
Addict Behav
(2003) Evidence for the presence of CB1 cannabinoid receptors on peripheral neurones and for the existence of neuronal non-CB1 cannabinoid receptors
Life Sci
(1999)- et al.
Neuroimaging of marijuana smokers during inhibitory processing: A pilot investigation
Brain Res Cogn Brain Res
(2005) - et al.
Delta-9-tetrahydrocannabinol effects in schizophrenia: Implications for cognition, psychosis, and addiction
Biol Psychiatry
(2005) - et al.
Cannabidiol increases Fos expression in the nucleus accumbens but not in the dorsal striatum
Life Sci
(2004)