CBD did not prevent THC's cognitive impairment or withdrawal in mice, but showed anxiolytic effects alone

Adding CBD to THC did not reduce THC-induced cognitive deficits or withdrawal signs in mice, but CBD alone produced anti-anxiety effects without causing dependence.

Myers, Alyssa M et al.·British journal of pharmacology·2019·Moderate EvidenceAnimal StudyAnimal Study
RTHC-02199Animal StudyModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

THC caused significant motor and cognitive impairment in Barnes maze; adding CBD did not attenuate these effects. Chronic THC caused CB1-mediated withdrawal signs; adding CBD did not reduce withdrawal. CBD alone did not impair cognition, did not cause CB1-dependent withdrawal, and produced anxiolytic effects that persisted even when attempting to precipitate withdrawal.

Key Numbers

THC caused significant Barnes maze impairment; CBD addition did not attenuate. Chronic THC withdrawal precipitated by SR141716; CBD addition did not reduce. CBD alone: no cognitive impairment, no CB1-dependent withdrawal, significant anxiolysis.

How They Did This

Multiple dose combinations of THC, CBD, and WIN55212 tested in C57BL/6 mice. Cognition assessed via conditional discrimination and Barnes maze. Withdrawal precipitated with SR141716 (CB1 antagonist), WAY100635 (5-HT1A), capsazepine (TRPV1), and SCH58261 (A2A).

Why This Research Matters

The popular belief that CBD counteracts THC's negative effects was not supported in this comprehensive animal study. However, CBD's standalone safety profile (no cognitive impairment, no dependence, anxiolytic) supports its therapeutic use as a monotherapy.

The Bigger Picture

This study challenges the widely held view that CBD can "balance out" THC in cannabis products. While CBD may modulate some THC effects at the receptor level, it did not protect against the clinically relevant outcomes of cognitive impairment and physical dependence in this model.

What This Study Doesn't Tell Us

Mouse model; CBD-THC interactions may differ in humans. Specific dose ratios tested may not reflect real-world cannabis use. CBD's anxiolytic mechanism (not CB1-mediated) warrants further exploration.

Questions This Raises

  • ?At what ratio does CBD modulate THC effects, if any?
  • ?Would higher CBD:THC ratios produce different results?
  • ?Does CBD's failure to prevent THC withdrawal translate to human cannabis users?

Trust & Context

Key Stat:
CBD did not counteract THC
Evidence Grade:
Moderate: comprehensive dose-range animal study with multiple behavioral endpoints and receptor-specific withdrawal precipitation.
Study Age:
Published in 2019.
Original Title:
Single and combined effects of plant-derived and synthetic cannabinoids on cognition and cannabinoid-associated withdrawal signs in mice.
Published In:
British journal of pharmacology, 176(10), 1552-1567 (2019)
Database ID:
RTHC-02199

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

Does CBD really counteract THC?

In this mouse study, adding CBD to THC did not reduce THC's cognitive impairment or withdrawal signs. The common belief that CBD "balances" THC was not supported.

Is CBD safe to use on its own?

CBD alone did not impair cognition, did not cause dependence or withdrawal, and produced anti-anxiety effects, supporting its safety as a standalone therapeutic agent.

Read More on RethinkTHC

Cite This Study

RTHC-02199·https://rethinkthc.com/research/RTHC-02199

APA

Myers, Alyssa M; Siegele, Patrick B; Foss, Jeffrey D; Tuma, Ronald F; Ward, Sara Jane. (2019). Single and combined effects of plant-derived and synthetic cannabinoids on cognition and cannabinoid-associated withdrawal signs in mice.. British journal of pharmacology, 176(10), 1552-1567. https://doi.org/10.1111/bph.14147

MLA

Myers, Alyssa M, et al. "Single and combined effects of plant-derived and synthetic cannabinoids on cognition and cannabinoid-associated withdrawal signs in mice.." British journal of pharmacology, 2019. https://doi.org/10.1111/bph.14147

RethinkTHC

RethinkTHC Research Database. "Single and combined effects of plant-derived and synthetic c..." RTHC-02199. Retrieved from https://rethinkthc.com/research/myers-2019-single-and-combined-effects

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.