Medicinal Cannabis for Sleep Did Not Impair Next-Day Driving or Cognition

At 9+ hours after evening administration of 10mg THC/200mg CBD oil, there were no differences from placebo on 27 of 28 cognitive and psychomotor tests, including simulated driving performance. The only difference was a small 1.4% decrease in accuracy on the easy Stroop task (but not the hard version). A slight increase in self-rated sedation at 10 hours was not accompanied by changes in alertness or sleepiness ratings.

Randomized, double-blind, placebo-controlled crossover trial with 20 adults (16 female, mean age 46.1) with physician-diagnosed insomnia who infrequently use cannabis. Each completed two 24-hour in-lab visits with 10mg THC/200mg CBD oil or placebo, with next-day testing at 9+ hours post-dose.

A major concern with medicinal cannabis for sleep is next-day impairment affecting driving and work safety. This study provides reassuring evidence that a typical medicinal dose does not produce meaningful next-day functional impairment in an insomnia population.

With increasing use of medicinal cannabis for sleep, evidence about next-day safety is critically needed for clinical guidelines and policy decisions around driving and workplace safety.

Small sample (n=20). Only one dose tested. Participants were cannabis-infrequent, so regular users may differ. Laboratory setting may not capture real-world conditions. The study examined a single dose, not cumulative effects of nightly use.