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.
Read this if you are interested in the neuroscience of appetite control and how different cannabinoids affect the brain.
THCV normalized an obesity-related brain connectivity pattern
What the researchers 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.
Why it 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 numbers in context
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 the study worked
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.
What this study cannot 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.
How to read the evidence
Well-designed crossover RCT with objective neuroimaging, but small sample, single dose, and no clinical outcomes measured.
When this study was published
Published in 2015. THCV research for metabolic conditions has continued.
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.
Questions still open
- 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?
Common questions
What is THCV?
Could THCV help with weight loss?
Read the original research
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)
Citation
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
Explore the wider topic
- How THC Affects Your Amygdala: The Brain's Threat Detector and Cannabis
- The Anandamide Connection: Your Body's Natural Bliss Molecule
- How Long for Cannabinoid Receptors to Return to Normal
- Cannabis and the Developing Brain: What Every Teenager (and Parent) Should Know
- Why Can't I Enjoy Anything Without Weed? The Science Behind It
- Dopamine Recovery After Quitting Weed: What the Science Says
- The Endocannabinoid System Explained Simply: What It Does and Why It Matters
- Your Endocannabinoid System Explained: Why Withdrawal Happens
- Your Nervous System After Quitting Weed: Fight or Flight
- Using Weed Under 18: What It Does to Your Developing Brain
- What THC Does to Your Brain: Why Withdrawal Happens
- THC and Your Prefrontal Cortex: What Cannabis Does to Your Decision-Making Brain
- Weed, Cortisol, and Stress: What Cannabis Does to Your Stress Hormones
- Weed and Memory: What the Science Says About THC and Your Hippocampus
- Weed and Motivation: Is Amotivational Syndrome Real?
- Weed and Your Nervous System: What THC Actually Does to Your Brain and Body
- How Weed Rewires Your Reward System (And How to Reset It)