Professors question the therapeutic potential of cannabis derivatives

Professors at the Faculty of Medicine of the Federal University of Juiz de Fora (UFJF), psychiatrists Alexander Moreira-Almeida and Alexandre de Rezende Pinto questioned the report “Adhesion to medical cannabis grows in Juiz de Fora”, published on June 26. The article, which can be read on the Tribuna website, highlights the increase in court cases involving the use of medical cannabis in the city. In the interview that follows, the two professors claim that there is a lack of scientific evidence that consistently proves the effects of substances present in plants for the treatment of different diseases.

Tribune – Why is marijuana considered a drug and what effects does it have on a person’s body?

Coordinator of the Alcohol and Drugs Clinic at HU-UFJF, Alexandre de Rezende Pinto – What makes marijuana a drug is its ability to generate addiction. There is an idea that marijuana is not so problematic, it does not generate dependence, but this is not true. As the individual begins to use it, a process of tolerance begins, that is, there is a need to use increasing doses. This is characteristic of dependence, along with withdrawal symptoms, that is, control over use is lost. And, in addition to addiction, there are several other harms that marijuana brings, starting with the fact that its use is a gateway to the search for other drugs, especially when it begins to be used early, in adolescence. This ends up increasing the susceptibility of this developing brain to seek substances with more intense effects. In addition, when a person is exposed, for example, to a smoke shop to buy marijuana, he has contact with other people and other drugs, which can also influence the search for other substances. There are also psychiatric problems that are associated with marijuana, for example with schizophrenia, depression, suicidal ideation and cognitive impairment.

Alexander Moreira-Almeida is the research coordinator of the Postgraduate Program in Health at UFJF (Photo: Olavo Prazeres/Arquivo TM)

Research Coordinator of the Postgraduate Program in Health at UFJF, Alexander Moreira-Almeida – We recently reviewed the evidence in this regard, and today there are hundreds of good quality studies. Several of them study 13- and 14-year-olds and accompany them for years. And, basically, what we see is that the individual who used marijuana in adolescence, for example, is two to four times more likely to develop schizophrenia than the general population. He is at increased risk of depression, attempted suicide, mortality, and has a lower average IQ than those who have never used marijuana.

– So, the beginning of use in adolescence is more harmful than for those who start later, for example?

Alexandre de Rezende Pinto – This is a variable. But, in terms of prognosis, this is true for any substance: the earlier a person starts using it, especially before age 18, the worse the results and consequences of use will be. What the data show, for example, is that the earlier, more frequently and intensively the individual uses marijuana, the greater this association with schizophrenia. Not that starting smoking weed at age 30 is okay. But the repercussion is much more harmful for the teenager, as with any substance, especially in the earlier use.

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– Can we talk about the medical use of cannabis?

Alexandre de Rezende Pinto – Marijuana contains a number of substances called cannabinoids. The two main ones are tetrahydrocannabinol (THC), which is addictive, causes the “ripple effects” (psychoactive effects) of marijuana, and most of the aforementioned problems associated with marijuana. And then there’s cannabidiol (CBD). The supposed positive effects would be related to CBD. I say supposed because the evidence is inconsistent. So it’s not “medical marijuana”. What has been discussed today is the therapeutic potential of CBD. But what we need to highlight is that only one substance in marijuana is being researched, still with inconsistent evidence, in most cases, for this therapeutic use.

Alexander Moreira-Almeida – Of course, it is important to pursue any type of therapeutic intervention that is effective (for treating disease). But this must be done with scientific rigor. These precautions must be taken for the use of any substance. There are thousands of substances being tested for depression, autism and Alzheimer’s, but they don’t get the same attention. This focus on marijuana raises suspicion that there are other interests, such as the finances of cannabis companies. In addition, it is essential to separate what is the use of cannabidiol (one of more than 200 substances in cannabis) from what is called “medical marijuana” and its recreational use. They are completely different things. Of course, it can have one, two or more substances with therapeutic effects, but that doesn’t mean that marijuana is therapeutic. There is a huge lack of good quality studies on the subject and this is fundamental. Almost everything that is announced about this for the layman has no scientific basis.

– What are the proven uses of drugs based on cannabis substances?

Alexandre de Rezende Pinto is coordinator of the Alcohol and Drugs Clinic at HU-UFJF (Photo: Pedro Salgado)

Alexandre de Rezende Pinto – What we have proven today is the use of CBD in the treatment of refractory epilepsy, that epilepsy condition in which the patient has frequent and daily seizures and for which no other type of medication, the so-called anticonvulsants, works. For that we have evidence, and something for chronic pain. For the treatment of other diseases such as autism, for Alzheimer’s, for example, there is no evidence.

– In your opinion, the term “medical cannabis” is inappropriate. Because?

Alexander Moreira-Almeida – The Federal Council of Medicine and the Brazilian Association of Psychiatry have already spoken out against the use of this term, as it is misleading. What should be focused on is the investigation of potential therapeutic effects of cannabinoid derivatives. With rigor, prudence, common sense and focus on the patient’s health. When medical marijuana is advertised, the perceived risk of marijuana is reduced. And there are studies – such as one published by the scientific journal “The New England Journal of Medicine” – showing that when the perception of risk is decreased, the rate of consumption increases, and when consumption increases, the rate of schizophrenia increases, attempts to suicide and car accidents, for example, and other problems associated with marijuana use. In addition, it can generate false hope for cure and relief among people dealing with serious illnesses, lead away from effective treatments and even generate deleterious side effects. The dissemination of the idea that marijuana is medical and that its recreational use is not problematic, generates an increase in consumption and the resulting harmful effects.