The rule introduced by the new Highway Code, in force since, has sparked a heated debate December 14, 2024which concerns those who start driving after taking psychotropic substances or narcotics. The novelty consists in the fact that you can be tested even in the absence of a clear state of psycho-physical alteration and sanctioned, with the suspension or revocation of the license for up to three years, if there is a positive test result for THC, (tetrahydrocannabinol), the psychotropic substance produced by cannabis flowers, traces of which can remain in the body even at several days after intake.
The process is complex but clear: if, after the initial checks, which may include a saliva test, there is reasonable reason to believe that the driver of the vehicle is under the influence resulting from the use of narcotic or psychotropic substances, the traffic police bodies can prepare a more in-depth toxicological analysis on samples taken and analyzed in the laboratory. Since this result may not be immediately available, the driving license can be immediately withdrawn (for a period not exceeding ten days) until the outcome of the investigations, preventing the driver from continuing to drive the vehicle.
If even the most in-depth toxicological analysis gives a positive result, the driver holding a driving license will have to undergo a medical examination within 60 days and, if his unfitness to drive is certified, his license will be revoked for three years. .
At the basis of the criticism, also raised publicly by the singer Vasco Rossi, is the decision to test even those who are not in an “evident state of psycho-physical alteration”. Although traces of THC are generally detectable up to 72 hours after taking cannabis, i.e. up to three days later, the same cannot be said of the psychotropic effects, which tend to disappear after a few hours.
However, scientific practice shows that the situation is a little more complex than one might think, that there are many variables involved and that they all lead back to what must always be considered as a subjective picture, which cannot be generalized.
To delve deeper into the topic with Vanity Fair she is the neuroscientist Grace Madeowith long experience in the field of neurophysiology and pathologies related to the alteration of dopamine function. Already a researcher at the National Institute on Drug Abusewhere he studied the mechanisms underlying dopaminergic dysfunction, Madeo is currently Director of the Neuromodulation and Clinical Research Unit of the Brain & Care Center.
«When we talk about psychoactive psychotropic substances – and in particular THC, therefore cannabis – we must take into consideration various factors, first of all the metabolism of these substances by each organism», he explains. «When they are hired for different modalities they can generate intermediate substances, called metabolites, capable of maintaining a residue of psychoactive and psychotropic activity, i.e. an action on our psychic abilities, our cognitive functions and our behaviors».
On the formation of these metabolites, in particular with regards to THC, a distinction must naturally be made between the occasional user, in whom “it is possible to detect the metabolites in the urine even up to three days after intake” and the regular user, which sometimes makes it consumed daily: «In this case, the doses taken and individual characteristics must also be taken into account», specifies Madeo. «It is important, for example, to consider the percentage of fat mass present in the body or the more or less high metabolism capacity. Because it is precisely all these factors that influence the residence time of these metabolites in biological samples such as saliva, urine, blood or hair.”
Is it possible that, three days after taking cannabis, there may still be effects on cognitive functions?
«From a neurological point of view it is necessary to evaluate case by case. Because if we see tout court the way in which these substances are absorbed, the times within which the psychotropic effects wear off, the inactive metabolites that exist in the following days we could naturally have a position. However, there may be individual characteristics that determine different effects on the level of our psyche and our cognition. Therefore, a very clear medical judgment in this regard can only be expressed on the basis of the characteristics of the subject.”
What can a biological test reveal?
«Basing only on a saliva test or a urine test will not give a precise indication of the level of intoxication. Certainly one of the most responsive tests in this sense is the blood test. In this case, the aspect that certainly needs to be clarified is that relating to cut off reference, i.e. what are the levels within which one falls into a state considered to be acute intoxication or not. These levels obviously require standardization. However, when we tackle this terrain we are also talking about people who use cannabis from a therapeutic point of view. In that context we are within a medical prescription, with certain dosages and naturally with a control of the formulations. I think this distinction needs to be mentioned.”
Does the finding of these metabolites in biological samples mean that psychotropic effects may also be present?
«It depends on the substances we take into consideration. If we always refer to the behavioral and psychological alterations induced by THC, they generally wear off within a few hours. However, there is a metabolite, the11 hydroxyTHCwhich may still have active effects, while others – detectable even for up to three days – may not have any. The possibility that a psychological behavioral alteration continues to occur also depends in this case on various factors: on whether the substance is consumed regularly and in consistent doses, on the individual’s ability to metabolise, on how much this substance is stored in the body. 11 hydroxyTHC has a slow elimination because, being a highly lipid-soluble substance, it binds to the fats of the adipose tissue and is eliminated slowly, even after 5 or 6 days in an occasional user or even after 15-30 days in a smoker. chronic cannabis, although this does not mean that throughout this period the person is in a constant state of psychophysical alteration”.
Is it true that cannabis in circulation today has a higher level of THC than that of twenty years ago?
«There are data from the Istituto Superiore di Sanità in this regard: today the formulations contain much higher percentages of THC and this brings us back to what we were talking about before: a person who uses it frequently and not necessarily in high quantities, can have then the consequences on the metabolites in circulation. There are also formulations that are not entirely pure, mixed with other substances, or let’s also think of synthetic cannabinoids. It is undoubtedly a very complex and delicate matter.”
What kind of effects does cannabis consumption produce and what impact can they have while driving?
«The alterations that are generally caused by the presence of THC concern our cognitive functions, specifically referring to our attention capacity. This ability can be reduced and reaction times can be altered, resulting in an increase. Let’s imagine, when we start driving, that there may be a sudden danger or an unexpected event: we need quick, prompt reaction times and these can be very slow. Furthermore, the visual perceptive ability may be altered, therefore, for example, the calculation of distances. We realize that these are all aspects that, when we get behind the wheel, are fundamental for driving safely, for being ready and braking or even for calculating the distances between one vehicle and another.”
Can the new rule introduced by the Highway Code then be considered a precautionary measure, dictated by the fact that in the case of taking psychotropic substances or narcotics, even after days, there are many variables to take into consideration?
«There is certainly an important distinction to be made between occasional use and regular use which can influence both the percentage of the presence of metabolites in the organism and on cognitive functions and mental activities. And there is also the need to introduce explanatory circulars for those who make therapeutic use of these substances. The fact remains that even substances such as alcohol, cocaine, methamphetamines can affect our abilities even the following day. But always based on the conditions of the consumer and the dose used. Let us remember that these substances alter our attentional abilities, our reaction times, our perception of distance, rather than the presence of our body in space. Based on our individual characteristics, no substance could be safe, especially when there is an alteration on a psychological and behavioral level. Personally I believe that we will see the effects of these measures on the reduction of road accidents and mortality in some time. Only in retrospect will we be able to say “okay, we did well” or “no, we didn’t do well”».
Source: Vanity Fair
I’m Susan Karen, a professional writer and editor at World Stock Market. I specialize in Entertainment news, writing stories that keep readers informed on all the latest developments in the industry. With over five years of experience in creating engaging content and copywriting for various media outlets, I have grown to become an invaluable asset to any team.
