Can a Study of Self-Selected Cannabis Edibles Rank Their Cognitive Effects?
A study can observe meaningful differences across cannabis product groups even when the groups started out with different characteristics. Martin-Willett and colleagues measured cognition before and after edible use in adults with chronic, nonspecific low back pain.
What the researchers compared
The 183 participants self-selected CBD-dominant, THC-dominant or mixed products. They took cognitive tests before use and at one and two hours. At one hour the CBD group performed better than the mixed group on working memory. Verbal learning scores were more stable in the CBD group. The paper found no statistically significant effects in some other domains, including executive function and processing speed.
Why product choice matters in testimony
Participants were not randomly assigned to products. The groups may differ in prior use, reasons for choosing a product or other factors that influence a test score. The study helps identify domains worth examining, while the design limits causal comparisons between products. The tasks also did not directly measure driving performance.
Martin-Willett et al., Psychopharmacology (2026)
