Cannabis should be avoided by young people, pregnant women and drivers – 08/31/2023 – Health

A review of meta-analyses of studies on cannabis pointed out that teenagers, young adults, pregnant women and people who are driving vehicles should avoid substance use. At the same time, he noted that cannabidiol (CBD) —one of the substances found in cannabis— is effective for epilepsy, especially in children, and that other cannabinoids may be beneficial in the treatment of multiple sclerosis, chronic pain, inflammatory bowel disease, and palliative care.

The review (a kind of review of reviews) sought to assess the quality, credibility and level of certainty of the existing associations between human health and cannabis, cannabinoids and medicine based on the substance. 101 publications were considered.

The work, which came out this Wednesday (30th) in the journal BMJ, included in its scope both observational studies and randomized controlled trials.

According to the scientists, cannabidiol can be considered as a potential treatment option for reducing seizures in cases of epilepsy.

Medicines made from cannabis their use may also be considered for different conditions associated with chronic pain. Among the examples cited by the scientists are multiple sclerosis, spasticity associated with multiple sclerosis, nausea and vomiting in people with various health conditions, and for sleep in cancer patients.

“Cannabidiol appears to be safe with regard to psychiatric symptoms, but more studies are needed before this drug is recommended for the treatment of psychiatric problems,” say the researchers.

Addressing those responsible for public health policies and other researchers, the review authors state that guidelines are needed to translate existing findings on the use of cannabis.

Care and Cannabis X Alcohol

According to the authors of the research, adolescents and young adults should avoid the use of cannabis because of neurodevelopment still ongoing. In addition, it is the time when mental health disorders begin and cognition is essential for learning and academic performance.

The researchers say that, in the case of young adults, consumption should be avoided when there is a tendency to mental health problems or if the person already has, in fact, such problems.

An association was also identified between the use of cannabis and psychosis.

In the analysis, the quality of the evidence found was considered. For the use case of cannabis associated with psychosis in adolescents, the evidence is of “highly suggestive, convincing credence in major sensitivity analyses”. For adults, “suggestive credibility, suggestive certainty.”

It is worth mentioning that, for observational studies —those in which there is no direct intervention by researchers, only subsequent observation and correlation—, the credibility of the evidence was classified as follows: convincing, highly suggestive, suggestive, weak or not significant.

In the case of randomized controlled studies —in short, research in which participants are randomly assigned to receive or not a substance, that is, there is a control group, which does not take a particular drug and serves as a comparison for the group that does— , the degree of certainty about the evidence ranges from high, moderate, low, or very low.

The scientists say they believe that the convergence of evidence between observational and randomized studies made by them strengthens the findings of the review.

(In case you were wondering, yes, there is a difference between meta-analyses —the basis of the review reported here— and systematic reviews, something that is more commonly seen out there. In short, meta-analyses rely more broadly on statistical methodology to analyze and draw conclusions from several studies already published.)

In general, it can be said that the review of meta-analyses observed that most of the results associated with the use of cannabinoids are supported by weak evidence (here considered observational studies), by low or very low certainty (here considered clinical trials randomized) or by non-significant evidence (taking into account both types of studies used in the review).

The point that certain groups should avoid substance use comes from convincing and converging evidence, say the review authors. Such evidence indicates, according to the scientists, that the use of cannabis it is associated with poor mental health and cognition and an increased risk of car accidents. Also, use during pregnancy can be harmful to babies.

“Other associations between cannabis and health outcomes are not supported by converging or convincing evidence,” say the review authors.

Researchers even compare the cannabis and alcohol. They cite the incongruity in the legislative treatment given to the two items in various parts of the world, especially considering the already widely known negative effects of alcohol in all age groups. Meanwhile, damages related to cannabis are concentrated between the ages of 10 and 24, say scientists.

“Furthermore, to the best of our knowledge, alcohol has no role as a medical treatment, while our research shows that cannabinoids may have beneficial effects in specific clinical conditions,” the researchers state. “The (scientific) rationale behind extreme or ideological legislative approaches, such as full legalization and commercialization of WAnnabiseven for young adults, versus a complete ban, and the different legislative requirements between cannabis and alcohol to disclose the associated risks to consumers, remains uncertain.”

Caution when reading the results

Like any study, there are limitations that must be taken into account in the results found. To begin with, when dealing with a topic that is still considered taboo in several regions of the world, when talking about cannabis and their use, we end up putting in the same package a great diversity of types of cannabis available, both legally and illegally.

Scientists cite, for example, the issue of tetrahydrocannabinol (THC) —one of several cannabinoids in the cannabis and what gets people “high”—which can vary considerably between legally and illegally obtained substances.

Furthermore, evidence from a decade ago (the review considered meta-analyses published from 2002 to 2022) may not be representative of the cannabis available both legally and illegally today, typically high in THC.