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Neurophysiological and subjective profile of marijuana with varying concentrations of cannabinoids

Aaron B Ilan, Alan Gevins, Michael J. Coleman, M. A. ElSohly, Harriet de Wit

Behavioural Pharmacology September 1, 2005 DOI: 10.1097/00008877-200509000-00023 (opens in new tab)

Relevant Not relevant

Study at a glance

AI-extracted from the abstract
Characteristics Randomized controlled trial Peer reviewed
Sample size 23
Population Healthy marijuana users
Intervention Smoked marijuana cigarettes containing placebo
Topics Cannabis CBD
Keywords Neurophysiology Electroencephalography Placebo Mood Audiology
Citations 165
Key findings Varying concentrations of cannabichromene and cannabidiol did not change subjective, behavioral, or neurophysiological responses to smoked marijuana, while THC produced expected effects on mood, behavior, and brain activity.

Abstract

This study investigated the contribution of different cannabinoids to the subjective, behavioral and neurophysiological effects of smoked marijuana. Healthy marijuana users (12 men, 11 women) participated in four sessions. They were randomly assigned to a low or a high delta9-tetrahydrocannabinol group (THC; 1.8% versus 3.6%). In the four sessions under blinded conditions subjects smoked marijuana cigarettes containing placebo (no active cannabinoids), or cigarettes containing THC with low or high levels of cannabichromene (CBC; 0.1% versus 0.5%) and low or high levels of cannabidiol (CBD; 0.2% versus 1.0%). Dependent measures included subjective reports, measures of cognitive task performance and neurophysiological measures [electroencephalographic (EEG) and event-related potential (ERP)]. Compared to placebo, active THC cigarettes produced expected effects on mood, behavior and brain activity. A decrease in performance, reduction in EEG power and attenuation of ERP components reflecting attentional processes were observed during tests of working memory and episodic memory. Most of these effects were not dose-dependent. Varying the concentrations of CBC and CBD did not change subjects' responses on any of the outcome measures. These findings are consistent with previous studies indicating that THC and its metabolites are the primary active constituents of marijuana. They also suggest that neurophysiological EEG and ERP measures are useful biomarkers of the effects of THC.

In the evidence

This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.

  • State of the evidence: CBD No effect

    Varying CBD (and cannabichromene) concentrations in smoked marijuana did not change subjective, behavioral, or neurophysiological responses, whereas THC produced the expected effects.

    Synthesized

Comparable studies

Other randomized controlled trials on cannabis, most cited first.

Study Year Design Participants
Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Healthy participants 2012 Randomized controlled trial n = 48
Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Healthy, English-native, right-handed men who had used cannabis 15 times or less in... 2009 Double-blind, randomized, placebo-controlled crossover trial n = 15
Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Healthy male subjects 2012 Randomized controlled trial n = 16
Modulation of Mediotemporal and Ventrostriatal Function in Humans by Δ9-Tetrahydrocannabinol Healthy, native English-speaking, right-handed men of white race/ethnicity who had used... 2009 Randomized controlled trial n = 15
Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Healthy volunteers with a history of light cannabis use 2019 Randomized, double-blind, within-subjects crossover n = 14

Citations in the library

Cited by 45

and 40 more in the library

Cites 4

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