- Source type
- Study
- Access type
- Publisher
- Publisher
- JAMA Network Open
- Date
- 2025-01-28
- Added
- 2026-07-04
Trust profile
VV Source Trust Matrix v1.0
VV Source Trust Matrix v1.0 asks whether this source is trustworthy for the claim lane being used, not whether every possible claim from it is equally strong.
88
Peer-reviewed research publisher
- Publisher type
- Peer-reviewed journal
- Bias profile
- Moderate
This source is strongest for clinical outcomes and mechanism and weaker for regulatory status and trial discovery.
VV Source Fit Score 1.0
Fit by use case
Fit scores are role-specific. A source can be excellent for one claim lane and weak for another.
- Regulatory status
- 65/100
- Context Source
- Clinical outcomes
- 92/100
- Primary Anchor
- Mechanism
- 90/100
- Primary Anchor
- Safety
- 86/100
- Strong Support
- Consumer context
- 72/100
- Context Source
- Trial discovery
- 65/100
- Context Source
Best used for
- Primary studies
- Systematic reviews
- Mechanistic research
Weak for
- Regulatory status
- Universal consumer recommendations
Used in Viral Vitalism
Does Cannabis Shrink Your Brain?
Roles: Primary source
Show section-level references
- Article source list
- The viral claim gets one thing right and one big thing wrong
- Blood flow, activation, volume, and memory are not the same claim
- The strongest recent negative signal is working memory in heavy young-adult users
- The better question is not 'does weed shrink your brain?'
- Does cannabis literally shrink the whole brain?
Brain Function Outcomes of Recent and Lifetime Cannabis Use
Roles: Primary source
Show section-level references
Claim ledger
Claims supported
Reviewed claim cards that cite this source in the evidence graph.
cannabis: The broad claim that cannabis shrinks your brain overstates
The broad claim that cannabis shrinks your brain overstates a mixed evidence base and swaps endpoints such as perfusion, activation, volume, and cognition.
cannabis: Heavy lifetime cannabis use has been associated with lower
Heavy lifetime cannabis use has been associated with lower working-memory task activation in young-adult fMRI data.
Related studies
Related sources
What are marijuana's long-term effects on the brain?
Government consumer-health context for long-term brain-effect framing and adolescent exposure cautions.
- Trust score
- 91
- Publisher
- National Institute on Drug Abuse
- Access
- Official
- Usage
- 5 connections
Dave Asprey Facebook post: cannabis brain shrinkage claim
Public-discourse source documenting the Facebook version of the claim. Use for claim-accountability context only, not as clinical evidence.
- Trust score
- 60
- Publisher
- Access
- Publisher
- Usage
- 4 connections
Dave Asprey X post: marijuana shrinks your brain
Public-discourse source documenting the viral claim. Use for claim-accountability context only, not as clinical evidence.
- Trust score
- 60
- Publisher
- X
- Access
- Publisher
- Usage
- 4 connections
Sanofi: Cenrifki approved in the EU for secondary progressive multiple sclerosis without relapses
Canonicalized from rapid brief sanofi-cenrifki-tolebrutinib-eu-spms-approval.
- Trust score
- 60
- Publisher
- Sanofi
- Access
- Publisher
- Usage
- 1 connection
Wall Street Journal: Sanofi Multiple Sclerosis Drug Gets EU Approval
Canonicalized from rapid brief sanofi-cenrifki-tolebrutinib-eu-spms-approval.
- Trust score
- 60
- Publisher
- Wall Street Journal
- Access
- Publisher
- Usage
- 1 connection
Discriminative properties of hippocampal hypoperfusion in marijuana users compared to healthy controls
Primary source behind the Amen hippocampal hypoperfusion claim. This supports a cerebral blood-flow / perfusion signal in marijuana users, not a structural brain-shrinkage claim.
- Trust score
- 91
- Publisher
- PubMed
- Indexed by
- PubMed
- Access
- Abstract/index
- Usage
- 5 connections