The legalization of cannabis is at the heart of many debates, accompanied by a series of questions and concerns in view of its possible medical and recreational use. Researchers wonder: How long do the effects of this substance actually last? Relayed in ScienceAlert, a meta-analysis (synthesis of several scientific studies on the same subject) reveals that a consumer can remain under its influence for three to ten hours.
While the relationship between alcohol intake and intoxication has been questioned many times over the past decades, impairment after cannabis use has never had the right to scientific research. thrust before 2021.
For this study, Danielle McCartney, nutritionist at the University of Sydney (USYD), and her team referenced eighty separate analyzes looking at the harmful effects of the main psychoactive component of cannabis: tetrahydrocannabinol, more commonly known as “THC”.
In order to know the impairment of cognitive functions in individuals under cannabis and its duration, the researchers reviewed 1,534 people who had been subjected to a driving test. “The results showed that the deficiency can last up to ten hours if high doses of THC are consumed orally. Nevertheless, the usual duration is four hours when lower doses are administered while smoking,” reports Danielle McCartney.
Although most driving skills typically return to normal within five hours of inhaling cannabis, this timeframe varies depending on several factors: THC content, how the drug was consumed, and regularity. of the socket.
This last characteristic has particularly interested scientists. “Impairment is much more visible in occasional users than in regular users. Regulars show a high tolerance to the effects, even if they do not escape some alteration. notes Thomas Arkell, behavioral pharmacologist at USYD.
Establish fair legislation
Several questions remain. Knowing that the effects do not last as long from one person to another, how can we predict how much cannabis impairs the faculties of each user? How to establish fair legislation?
“Our jurisdiction needs to catch up and focus on the interval in which users pose a greater risk to themselves and others, suggests Iain McGregor, psychopharmacologist at USYD. Prosecutions solely based on the presence of THC in blood or saliva are unfair since it can be detected in the body weeks after consumption. However, we know that the deficiency lasts much less long.
More research will need to be conducted to best characterize the effects of THC. This information will thus help to sharpen the advice given to patients, to make recreational users aware of the consequences of cannabis, but above all, to guide legislation.