2026/03/20 by Justin Matheson, Christina Zakala, Sampson Zhao +7 · 1 voice
Medicine · Psychology · #Cannabis and Cannabinoid Research #Substance Abuse Treatment and Outcomes #Sleep and related disorders
paper · doi:10.1016/j.dadr.2026.100432
openalex publication_date 2026/03/20 · openalex created_date 2026/03/21 · openalex updated_date 2026/06/16
To examine next-day cognitive performance and subjective drug effects after smoking cannabis and to assess associations between performance and cannabinoid concentrations in blood and oral fluid. In this observational study, healthy adults who regularly used cannabis (mean age 30 years; n=65) smoked a legally purchased pre-rolled “joint” at night and were tested the next day, 12-15 hours later. Healthy adults with no past-month cannabis use served as a matched control group (mean age 30; n=65). Participants completed cognitive tasks (verbal free recall [VFR], Trail Making Test [TMT]), subjective effects questionnaires (including visual analogue scales [VAS]), and provided blood and oral fluid samples for quantification of delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), and metabolites. Linear regression models compared groups across cognitive/subjective outcomes, while Pearson correlations assessed associations between cannabinoid concentrations and performance. There were no significant group differences on any cognitive measure. The cannabis group had significantly elevated VAS ratings (e.g., feeling a drug effect, Δmean=12.54, p <0.01) compared to controls. Within the cannabis group, smoking infused (higher-THC-content) “joints” and higher %THC cannabis were associated with poorer verbal recall performance (e.g., %THC correlated with delayed verbal recall, r=-0.36, p<0.01). Higher blood THC and THC-COOH concentrations correlated with poorer VFR and slower TMT performance, whereas blood 11-OH-THC and oral fluid THC correlated with TMT performance only (all p≤0.03). There was no measurable next-day cognitive impairment, despite some subjective intoxication. Nonetheless, higher THC potency and elevated cannabinoid concentrations were associated with poorer verbal memory and processing speed, suggesting potential next-day impairment with high-THC products. • Frequent cannabis users were tested 12-15 hours after smoking cannabis at home • There was no evidence of cognitive impairment relative to a matched control group • Subjective drug effect measures were elevated relative to the control group • Higher THC levels were associated with worse cognitive performance