rtant to note, however, is that the current study was conducted in a controlled laboratory environment, and it is possible that the results may not generalize to real-world settings.
Cannabis Does Not Cause “Next-Day Impairment,” New Study Shows
In a groundbreaking new study published last week in the journal Psychopharmacology, researchers have found that cannabis does not cause “next-day impairment.” This finding contradicts common misconceptions and challenges long-held beliefs about the effects of THC on a person’s performance the day after consuming cannabis.
The study, conducted by a team of researchers from Macquarie University, the University of Sydney, Royal Prince Alfred Hospital, Griffith University, and Johns Hopkins University, observed 20 adults with physician-diagnosed insomnia who consumed cannabis irregularly. The data was gathered from a larger study investigating the effects of THC and CBD on insomnia.
Since the participants were taking THC and CBD right before bedtime, it was the perfect pool of subjects to examine next-day effects. They were randomly selected to receive either a 2 ml dose of cannabis oil containing 10 mg THC and 200 mg CBD, or a placebo.
Within two hours of waking up, participants were asked to complete cognitive tasks and psychomotor tests. The results showed that those who took 10 mg of THC, the intoxicating ingredient in cannabis, showed little to no impairment the next day. This suggests that it is entirely safe to drive after consuming cannabis the night before. In fact, those who took THC before bedtime performed exceptionally well on the tests the next day.
The study found that there were “no differences in ‘next day’ performance in 27 out of 28 tests of cognitive and psychomotor function and simulated driving tests relative to placebo.”
“The use of cannabis by night as a sleep aid is highly prevalent and there are legitimate concerns that this may lead to impaired daytime (‘next day’) function, particularly on safety sensitive tasks such as driving,” said the researchers. The study was written by Anastasia Suraev, Danielle McCartney, Nathaniel S. Marshall, Christopher Irwin, Ryan Vandrey, Ronald R. Grunstein, Angela L. D’Rozario, Christopher Gordon, Delwyn Bartlett, Camilla M. Hoyos, and Iain S. McGregor. Many of these researchers are associated with the University of Sydney’s Lambert Initiative for Cannabinoid Therapeutics and have studied cannabis impairment in the past.
“The results of this study indicate that a single oral dose of 10 mg THC (in combination with 200 mg CBD) does not notably impair ‘next day’ cognitive function or driving performance relative to placebo in adults with insomnia disorder who infrequently use cannabis,” the study reads. “Larger studies in patient populations are required to determine the effects of repeated dosing with THC (with or without CBD), and at higher doses of THC, on ‘next day’ function.”
The researchers associated with the Lambert Initiative have also found data showing that impairment from THC only lasts for a few hours, while drug tests can detect THC for weeks or even months after consumption. This means that drug tests may not accurately reflect a person’s current level of impairment.
While the study did show minor changes in cognitive function, further tests revealed that these changes were likely insignificant. However, it is important to note that the study was conducted in a controlled laboratory environment, and the results may not necessarily apply to real-world settings.
