Brain imaging revealed the insula plays a key role in the THC "high"
THC increased blood flow and activity in the insula, a brain region involved in body awareness, and these changes correlated with subjective feelings of being high.
Quick Facts
What This Study Found
Twenty-three subjects underwent pharmacological MRI after receiving THC or placebo. Using arterial spin labeling to measure blood flow, researchers found THC increased perfusion in the anterior cingulate cortex, superior frontal cortex, and insula, while reducing it in the post-central and occipital regions.
Resting-state fMRI showed increased baseline brain activity (measured by signal fluctuation amplitude) in the insula, substantia nigra, and cerebellum after THC. Frontal cortex perfusion changes were negatively correlated with "feeling high" ratings.
The insula findings were particularly notable because this region processes interoceptive awareness, the brain's perception of internal body states. The authors proposed that THC-induced changes in the insula may be central to the subjective experience of "feeling high."
Key Numbers
23 subjects. THC increased perfusion in anterior cingulate, superior frontal cortex, and insula. Reduced perfusion in post-central and occipital regions. Increased resting-state activity in insula, substantia nigra, and cerebellum.
How They Did This
Pharmacological MRI study with 23 subjects. Combined arterial spin labeling (for perfusion) and resting-state fMRI (for baseline activity). THC was compared to placebo. Subjective "feeling high" ratings were correlated with imaging measures.
Why This Research Matters
Understanding the neural basis of the cannabis "high" helps explain both its recreational appeal and potential therapeutic mechanisms. The insula's role in interoceptive awareness connects the subjective experience to a specific brain mechanism.
The Bigger Picture
The insula is implicated in addiction, anxiety, and pain processing. Understanding its role in THC effects helps connect the subjective cannabis experience to clinical conditions where the insula is involved.
What This Study Doesn't Tell Us
Acute single-dose design. The sample was healthy volunteers, not regular cannabis users. ASL perfusion measurement has lower signal-to-noise ratio than traditional fMRI. Heart rate effects of THC can confound blood-flow-based imaging.
Questions This Raises
- ?Does the insula response change with regular cannabis use?
- ?Could insula activity predict individual differences in THC response?
- ?Do cannabis users with anxiety show different insula patterns?
Trust & Context
- Key Stat:
- Insula activity linked to subjective "feeling high" ratings
- Evidence Grade:
- Well-designed pharmacological MRI study with reasonable sample size and dual imaging modalities. Heart rate effects of THC are a known confound for perfusion imaging.
- Study Age:
- Published in 2011. The insula's role in cannabis effects has been confirmed and expanded in subsequent neuroimaging studies.
- Original Title:
- Evidence for involvement of the insula in the psychotropic effects of THC in humans: a double-blind, randomized pharmacological MRI study.
- Published In:
- The international journal of neuropsychopharmacology, 14(10), 1377-88 (2011)
- Authors:
- van Hell, Hendrika H(4), Bossong, Matthijs G(7), Jager, Gerry(5), Kristo, Gert, van Osch, Matthias J P, Zelaya, Fernando, Kahn, René S, Ramsey, Nick F
- Database ID:
- RTHC-00528
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 part of the brain makes you feel high?
This study found the insula, a brain region that processes awareness of internal body states, was particularly active after THC. Changes in insula activity correlated with how "high" people felt, suggesting it plays a central role in the subjective cannabis experience.
Why did frontal cortex changes go the opposite direction?
Frontal cortex perfusion changes were negatively correlated with feeling high, meaning less frontal activation was associated with more intense subjective effects. This may reflect reduced cognitive control contributing to the altered state of consciousness.
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Cite This Study
https://rethinkthc.com/research/RTHC-00528APA
van Hell, Hendrika H; Bossong, Matthijs G; Jager, Gerry; Kristo, Gert; van Osch, Matthias J P; Zelaya, Fernando; Kahn, René S; Ramsey, Nick F. (2011). Evidence for involvement of the insula in the psychotropic effects of THC in humans: a double-blind, randomized pharmacological MRI study.. The international journal of neuropsychopharmacology, 14(10), 1377-88. https://doi.org/10.1017/S1461145711000526
MLA
van Hell, Hendrika H, et al. "Evidence for involvement of the insula in the psychotropic effects of THC in humans: a double-blind, randomized pharmacological MRI study.." The international journal of neuropsychopharmacology, 2011. https://doi.org/10.1017/S1461145711000526
RethinkTHC
RethinkTHC Research Database. "Evidence for involvement of the insula in the psychotropic e..." RTHC-00528. Retrieved from https://rethinkthc.com/research/van-2011-evidence-for-involvement-of
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.