Effects of naturalistic doses of cannabis edibles on cognition and association with blood THC.
Patricia Di Ciano, Sampson Zhao, Pamela Kaduri, Siddhi Patel, Kruti Bhakta, Christine M Wickens, Sheng Chen, Bernard Le Foll, Bruna Brands
Psychopharmacology March 1, 2026 Peer reviewed DOI: 10.1007/s00213-025-06863-2 via PubMed
Summary
After consuming a low-dose cannabis edible (average 7.3 mg THC), 22 regular users showed decreased performance on verbal free recall tasks at 150 minutes. No effects were found on visual attention or executive function tests. Blood THC levels did not correlate with any cognitive measures, though subjective intoxication increased. The findings suggest that even low-dose cannabis edibles can impair memory during intoxication.
Study at a glance
| Design | observational study |
|---|---|
| Sample size | 22 |
| Population | regular users of legally sourced cannabis edibles |
| Key finding | Low-dose cannabis edibles impaired verbal free recall but not visual attention or executive function, and blood THC was not correlated with cognitive performance. |
Abstract
Smoked cannabis is known to have effects on cognitive function. The use of edibles is on the rise yet there are few studies of the effects of edibles on cognitive function. Further, most studies of cannabis used fixed laboratory doses which may not capture some of the nuances of more naturalistic doses. Delta-9-tetrahydrocannabinol (THC) is the psychoactive component of cannabis yet the relationship of blood THC to cognitive performance is unclear. In the present observational study participants (n = 22) were invited to the lab to use their regular legally sourced cannabis edibles. At 150 and 270 min after ingesting the edible, measures of learning and memory (verbal free recall task), executive function (trail making test) and functional vision and visual attention (useful field of view test) were taken. Subjective experiences were also measured, and blood THC was correlated with cognitive outcomes. At 150 min after taking a cannabis edible (mean 7.3 ± 2.9 mg of delta-9-tetrahydrocannabinol) decreases were seen in performance on two measures of the verbal free recall. No effects were found on the useful field of view and trail making tests. There were significant increases in subjective experiences as assessed with a visual analog scale and the Addiction Research Centre Inventory; some changes were also seen on the Profile of Mood States. Blood THC was not correlated with any cognitive outcomes. In sum, the present results suggest that people who choose to use relatively low doses of cannabis edibles may experience decrements in cognitive function while experiencing intoxication.