THC boosted brain activity in attention networks, and a common gene variant influenced the effect

THC increased blood flow in brain areas involved in attention and salience processing, and the COMT gene variant modulated how the executive network responded, suggesting prefrontal dopamine levels affect cannabis susceptibility.

Bossong, Matthijs G et al.·European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology·2019·Moderate EvidenceRandomized Controlled Trial
RTHC-01958Randomized Controlled TrialModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Randomized Controlled Trial
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

THC increased perfusion in bilateral insula, medial superior frontal cortex, and left orbital frontal gyrus. The orbital frontal area showed decreased connectivity with the precuneus. THC effects on left insula perfusion correlated with subjective changes in perception and relaxation. COMT genotype significantly modulated THC effects, with Val/Met heterozygotes showing increased executive network perfusion after THC while other genotypes did not.

Key Numbers

39 healthy volunteers. THC increased perfusion in bilateral insula, medial superior frontal cortex, left middle orbital frontal gyrus. Left insula perfusion correlated with subjective perception/relaxation changes. COMT Val/Met heterozygotes showed unique executive network response.

How They Did This

Pharmacological MRI study with 39 healthy volunteers. Used Arterial Spin Labelling for perfusion and fMRI for resting state connectivity. Examined THC effects and their modulation by COMT Val158Met genotype.

Why This Research Matters

This study identifies a specific gene (COMT) that influences individual vulnerability to acute THC effects, providing a biological basis for why cannabis affects people differently. The COMT gene is already known to influence prefrontal dopamine levels.

The Bigger Picture

Individual differences in cannabis response are clinically important but poorly understood. Linking a well-characterized gene (COMT) to specific brain responses to THC moves the field toward precision approaches to cannabis risk assessment.

What This Study Doesn't Tell Us

Sample size of 39 limits genetic subgroup analysis power. Single acute THC dose may not represent chronic use patterns. Only one genetic variant examined. Healthy volunteers may not represent clinical populations.

Questions This Raises

  • ?Does COMT genotype predict long-term cannabis outcomes?
  • ?Would other dopamine-related genes show similar modulation?
  • ?Could COMT genotyping help identify who should avoid cannabis?

Trust & Context

Key Stat:
Gene variant modulates THC response
Evidence Grade:
Rated moderate because this is a controlled pharmacological imaging study, though sample size limits genetic analysis power.
Study Age:
Published in 2019.
Original Title:
Acute effects of ∆9-tetrahydrocannabinol (THC) on resting state brain function and their modulation by COMT genotype.
Published In:
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 29(6), 766-776 (2019)
Database ID:
RTHC-01958

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled TrialGold standard for testing treatments
This study
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Participants are randomly assigned to treatment or placebo groups to test cause and effect.

What do these levels mean? →

Frequently Asked Questions

Why does cannabis affect people differently?

This study found that the COMT gene, which influences dopamine levels in the prefrontal cortex, modulated how the brain responded to THC. People with different COMT variants showed different brain activation patterns.

What brain areas does THC activate?

THC increased activity in the salience network, particularly the insula and frontal areas. These regions are involved in attention, self-awareness, and processing the relevance of stimuli.

Read More on RethinkTHC

Cite This Study

RTHC-01958·https://rethinkthc.com/research/RTHC-01958

APA

Bossong, Matthijs G; van Hell, Hendrika H; Schubart, Chris D; van Saane, Wesley; Iseger, Tabitha A; Jager, Gerry; van Osch, Matthias J P; Jansma, J Martijn; Kahn, René S; Boks, Marco P; Ramsey, Nick F. (2019). Acute effects of ∆9-tetrahydrocannabinol (THC) on resting state brain function and their modulation by COMT genotype.. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 29(6), 766-776. https://doi.org/10.1016/j.euroneuro.2019.03.010

MLA

Bossong, Matthijs G, et al. "Acute effects of ∆9-tetrahydrocannabinol (THC) on resting state brain function and their modulation by COMT genotype.." European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 2019. https://doi.org/10.1016/j.euroneuro.2019.03.010

RethinkTHC

RethinkTHC Research Database. "Acute effects of ∆9-tetrahydrocannabinol (THC) on resting st..." RTHC-01958. Retrieved from https://rethinkthc.com/research/bossong-2019-acute-effects-of-9tetrahydrocannabinol

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.