Cannabis Compound THCV Changes Brain Network Connectivity in Ways Relevant to Obesity
A single dose of THCV, a cannabis-derived CB1 neutral antagonist, reduced default mode network connectivity and increased executive control network connectivity in healthy volunteers, suggesting potential for obesity treatment.
Quick Facts
What This Study Found
Researchers gave 20 healthy volunteers a single 10mg oral dose of THCV or placebo in a randomized crossover design, then scanned their brains with resting-state fMRI.
THCV produced no subjective effects (no feeling of being high), as expected for a CB1 neutral antagonist. However, it significantly altered brain network connectivity: reducing connections between the amygdala and the default mode network while increasing connections between the amygdala and the dorsal anterior cingulate cortex (part of the executive control network).
Under placebo, amygdala-precuneus connectivity correlated positively with body mass index. This correlation disappeared under THCV, suggesting the drug may normalize an obesity-related brain connectivity pattern.
Key Numbers
20 volunteers; 10mg oral THCV; no subjective effects; reduced default mode network connectivity; increased cognitive control network connectivity; BMI correlation with amygdala-precuneus connectivity eliminated under THCV
How They Did This
Randomized, within-subject, double-blind, placebo-controlled study. 20 healthy volunteers received 10mg oral THCV or placebo. Resting-state fMRI with seed-based connectivity analyses. Regions of interest: amygdala, insula, orbitofrontal cortex, dorsal medial prefrontal cortex.
Why This Research Matters
The CB1 inverse agonist rimonabant was effective for obesity but caused depression. THCV is a neutral antagonist, meaning it blocks the receptor without the inverse agonist activity that may cause psychiatric side effects. This study suggests THCV affects brain networks relevant to obesity without mood changes.
The Bigger Picture
THCV could potentially offer the weight-management benefits of CB1 blockade (like rimonabant) without the depression and anxiety that led to rimonabant's withdrawal. These early brain imaging findings support further investigation.
What This Study Doesn't Tell Us
Very small sample (n=20). Single dose only. Healthy volunteers, not obese individuals. No measurement of food intake or weight. Resting-state connectivity changes do not prove clinical efficacy.
Questions This Raises
- ?Would chronic THCV dosing produce sustained brain changes and weight loss?
- ?Does THCV truly avoid the psychiatric side effects of rimonabant?
- ?Would these connectivity changes be more pronounced in obese individuals?
Trust & Context
- Key Stat:
- THCV normalized an obesity-related brain connectivity pattern
- Evidence Grade:
- Well-designed crossover RCT with objective neuroimaging, but small sample, single dose, and no clinical outcomes measured.
- Study Age:
- Published in 2015. THCV research for metabolic conditions has continued.
- Original Title:
- The CB1 Neutral Antagonist Tetrahydrocannabivarin Reduces Default Mode Network and Increases Executive Control Network Resting State Functional Connectivity in Healthy Volunteers.
- Published In:
- The international journal of neuropsychopharmacology, 19(2) (2015)
- Authors:
- Rzepa, Ewelina, Tudge, Luke(2), McCabe, Ciara(2)
- Database ID:
- RTHC-01055
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
What is THCV?
Tetrahydrocannabivarin (THCV) is a naturally occurring cannabinoid in cannabis that acts as a neutral antagonist at CB1 receptors. Unlike THC, it does not produce a high. It has been investigated for appetite suppression and metabolic effects.
Could THCV help with weight loss?
This study showed THCV changes brain connectivity in ways associated with obesity, without causing mood changes. However, it was a small brain imaging study in healthy volunteers, not a weight loss trial. More research is needed.
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Cite This Study
https://rethinkthc.com/research/RTHC-01055APA
Rzepa, Ewelina; Tudge, Luke; McCabe, Ciara. (2015). The CB1 Neutral Antagonist Tetrahydrocannabivarin Reduces Default Mode Network and Increases Executive Control Network Resting State Functional Connectivity in Healthy Volunteers.. The international journal of neuropsychopharmacology, 19(2). https://doi.org/10.1093/ijnp/pyv092
MLA
Rzepa, Ewelina, et al. "The CB1 Neutral Antagonist Tetrahydrocannabivarin Reduces Default Mode Network and Increases Executive Control Network Resting State Functional Connectivity in Healthy Volunteers.." The international journal of neuropsychopharmacology, 2015. https://doi.org/10.1093/ijnp/pyv092
RethinkTHC
RethinkTHC Research Database. "The CB1 Neutral Antagonist Tetrahydrocannabivarin Reduces De..." RTHC-01055. Retrieved from https://rethinkthc.com/research/rzepa-2015-the-cb1-neutral-antagonist
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.