By Antônio Geraldo da Silva, M.D.
Recently, Brazil became one of the many countries that authorized the prescription and manipulation of medications that contain cannabidiol and tetrahydrocannabinol (THC), active constituents of marijuana. In practice, THC has also been legalized. Before, the component was only allowed in secondary form, that is, as part of the composition of legal medications. The subject was discussed in the National Institutes of Health (NIH) and we’re still far from a medical consensus on the theme.
Source: Source: Courtesy Antônio Geraldo da Silva
As a doctor and psychiatrist, I categorically disagree that there is such a thing as medical marijuana, even though many believe the opposite. As any illicit drug, marijuana takes up a lot of space in society’s imagination and has been gaining an aura of benignity without reliable scientific evidence. The truth is that it’s naïve and wrong to say that marijuana is a light drug or a therapeutic drug.
Much has been written about the harmful effects of marijuana when inhaled in the form of smoke, but most of the papers on the subject didn’t make it sufficiently clear to the general public that the toxic potential associated with marijuana depends mainly on two factors: the beginning of use during adolescence and the frequency and amount of use. In the first case, the use of the substance will have a greater chance of interfering with the development of the brain, harming the elimination of unused neural connections and the development of white matter, which coordinates communication between different brain regions. In the second case, the greater or more potent the dose, the higher the absorption of THC. This substance acts over areas of the brain that are involved in the regulation of emotions.
There are those who smoke marijuana and remain unharmed, but many people experience the opposite. There’s evidence that the use of marijuana worsens common psychiatric conditions, such as schizophrenia, depression and bipolar disorder. The continuous use of marijuana may cause psychotic disorders after an average of two to seven years. The risk of developing schizophrenia, for example, is twice as high for users compared to non-users.
Even though the manner in which marijuana acts in the development of psychoses hasn’t been perfectly understood, the association causes no surprise. The strongest, temporary effects of the drug are very similar to the symptoms of psychoses, including memory and cognition deficit and distortion of external stimuli. While the drug is active, users frequently experience difficulty in learning new things and remembering something, and may even come to have delusions and hallucinations. It has been proven that the use of this substance can cause the first serious crises of some mental disorders, altering the natural history of patients that could go through life uninjured by genetically transmitted risks.
It may even be true that THC and cannabidiol have some effect in the treatment of epilepsy and multiple sclerosis, but the best of science is still unable to state that with certainty. The FDA itself has never approved the clinical use of these two components of marijuana. This discussion, therefore, is urgent. Before we reach any conclusions, the authorities need to make more information on the subject available. Only after that’s done will the population be able to discuss this subject with more accuracy and with the attention it deserves.
Antônio Geraldo da Silva is the president of the Brazilian Association of Psychiatry (ABP)