CBD and driving: should you choose?

CBD, or cannabidiol, is a non-psychoactive substance known for its many benefits, but less so for its possible effects when behind the wheel. Although legal in Switzerland if it contains less than 1% THC, it is still associated in people's minds with the psychoactive effects of THC, which is of course illegal and incompatible with driving. So what does science have to say about the impact of CBD consumption on road safety?

Consuming CBD and driving: you don't have to choose. 2 recently published studies, one in September 2021, the other in December 2020, reveal that consumption of CBD-dominant cannabis does not affect driving ability.

One such study, published in December 2020 in the Journal of the American Medical Association, was led by the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney. It involved 26 participants who "vaped" cannabis containing different ratios of THC and CBD, then drove a 100-kilometer route under controlled conditions on public roads. For Dr Thomas Arkell, the result was very clear: "CBD does not affect driving ability".

What does the 1st global study on the effect of CBD consumption on driving say?

"To our knowledge, this is the first study to assess the potential impact of this consumption on road safety," explain the authors of the Swiss study published a few months ago, Tim J. Gelmi, Wolfgang Weinmann and Matthias Pfäffli.

Source : https://pubmed.ncbi.nlm.nih.gov/34868711/

Published in the renowned PubMed database, which brings together 33 million articles and studies related to biology and medicine, the authors set themselves the ambitious goal ofassessing the impact of CBD on psychomotor and cognitive abilities related to driving. In short, it's everything we need to analyze a situation, make a decision and react once we're behind the wheel.

33 volunteers were divided into 2 groups. One group received a placebo, while the second consumed CBD-dominant cannabis (16.6% CBD and 0.9% THC, below the legal threshold of 1% in Switzerland).

These volunteers then underwent :

• on the one hand, tests forming part of a measurement system commonly used (in 26 countries) to assess driving ability,

• on the other hand, balance and coordination exercises regularly used by police officers in Switzerland in the event of traffic offences or checks, to see if there are any physical impairments due to drug or alcohol consumption.

Reaction time, behavior in stressful situations, ability to concentrate, balance, coordination, blood pressure, etc. Everything has been assessed and recorded to establish what, if any, risks are involved behind the wheel.

What conclusions can we draw?

The conclusions are very clear: 

Focus on reaction time

When you think of the association between cannabidiol and driving, you might think of slower reaction times and reflexes. But the figures are there: for the series of tests based on light and sound stimuli, the group that consumed the cannabinoid had an average reaction speed of 60.6 s, while that of the placebo consumers was barely above that (61.0 s). Only one blink (0.4 s on average) separated the two averages.

CBD does not affect coordination

In order to prevent accidents on the road, you need to be able to rely on flawless coordination. In this global study, the researchers established that, out of 66 coordination tests, 6 were outside the so-called normal reaction time range, set at between 20 and 45 seconds. 

Interestingly, of these 6 marginal cases, only one involved a person who had taken CBD (the hypothesis being that this person may not have fully understood the instructions). The other 5 cases concern only people who took the placebo. 

What if CBD offset the negative effects of THC?

Researchers have established that CBD helps regulate the negative effects of THC:

• tachycardia, 
• anxiety, 
• perspiration, 
• difficulty concentrating, ...

So a real inversion can take place! When these two cannabinoids are combined in the right ratio, they can erase the known negative effects of THC. It's the same family, but with different effects.

Consuming CBD, driving: what to expect during a control?

In Switzerland, CBD is legal if the THC threshold is set below 1%. But what can you expect when you get behind the wheel: withdrawal of your license, complaints during a roadside check, penalties, etc.? At what dose can you be considered positive during a police or other anti-drug check?

As this cannabinoid is legal, there is no risk of testing positive for this substance. The question is more how concentrated the products are in THC.

In a fact sheet on the regulation of cannabidiol consumption in relation to driving, the Swiss Federal Office of Public Health (FOPH) provides a number of facts, based on a study carried out by the Institute of Forensic Medicine at the University of Basel*. In particular, the THC limit is 1.5 micrograms per liter of blood. In other words, if a person is found to have this level of THC in their blood, they are automatically considered unfit to drive.

source : Bucher, B., Gerlach, K., Frei, P., Knöpfli, K., Scheurer, E. (2020): Bericht THC-Grenzwerte im Strassenverkehr - eine Literaturanalyse. Institut für Rechtsmedizin der Universität Basel, Basel

Warning: with the Sicura law law in force in Switzerland, saliva tests carried out on the road are used to determine whether or not THC has been consumed, whatever the level. If the answer is yes, and even if the level detected is below the punishable level, the driver's license is withdrawn.

Only after the samples have been analyzed, i.e. to determine the true THC concentration in the blood, can the driver's license be restored (if it's less than 1.5 µg/L). This can take several months.

2 issues: concentration and timing of consumption

So there are 2 things to watch out for: 

• the THC concentration of products: whether cannabis flowers, oils or other edible products, all of which, depending on the method of production, may be free of THC or have a high THC content and therefore be positive when tested

• the time of consumption. In expert studies, the THC level in the blood immediately after consumption is 2.6 micrograms per liter of blood, whereas 45 minutes later it is 0.9 mg/mL. The Australian study shows that 4 hours after consumption of cannabis with moderate to high THC content, there is no longer any effect of THC on driving.

Driving and CBD aren't for you? You can use the broad-spectrum CBD oil found in our Wellness THC-FREE oils. This is CBD extracted from hemp or cannabis and processed to remove THC from other cannabinoids.

Written by Naturalpes

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