Effects of delta-9 tetrahydrocannabinol and cannabidiol on cognitive outcomes following acute use of cannabis for chronic pain.

Martin-Willett R.; Melendez S.; Hutchison K.; Bryan A.; Bidwell L. · Psychopharmacology · 2026

**Background & Methods** This review examined acute cognitive effects of cannabis use in 183 medical cannabis users (mean age 45.6 years, 56.8% female) with chronic non-specific low back pain. Participants self-selected into three edible cannabis groups: CBD-dominant, THC-dominant, or mixed CBD:THC ratio, and completed cognitive testing batteries (assessing executive function, processing speed, memory, and verbal learning) at baseline, 1 hour post-use, and 2 hours post-use. **Key Findings** • CBD-dominant cannabis users demonstrated superior working memory performance at 1 hour post-use compared to mixed CBD+THC users, with more stable verbal learning scores across timepoints than both THC-dominant and mixed-ratio groups. • Age-related benefits in working memory observed in the CBD group at baseline progressively diminished at subsequent timepoints, suggesting temporal modulation of cognitive effects. • No significant cognitive impairment was detected in executive function, episodic memory, or processing speed domains across any cannabis group or timepoint. **Dosage & Administration** Not reported. The abstract does not specify cannabis doses, cannabinoid concentrations, or standardized dosing regimens used by participants in any group. **Safety & Adverse Effects** Not reported. The abstract does not detail adverse events, side effects, or safety outcomes associated with acute cannabis use in this population. **Evidence Quality** This review has notable limitations affecting evidence quality. The observational, self-selected group design introduces selection bias and confounding variables. Self-administration of non-standardized edible products limits dose precision and comparability. The cross-sectional timeframe captures only acute effects within 2 hours, precluding assessment of sustained or delayed cognitive impacts. Sample size (N=183) is modest for detecting subtle between-group differences. The abstract does not specify whether cognitive testing was blinded or controlled for baseline differences. Importantly, this appears to be a review paper rather than original research, which may further limit direct evidence generation. These limitations suggest findings should inform rather than definitively guide clinical practice, and highlight the need for controlled trials with standardized cannabinoid formulations and longer follow-up periods.

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