En el presente trabajo se realiza una reflexión acerca de si el exponer, conocer y precisar los efectos de la marihuana en la adolescente embarazada y en el producto de la gestación serían un factor determinante para poder considerar más juiciosamente la tendencia a legalizar la marihuana en México. Se enfatizan las alteraciones descritas sobre el sistema nervioso central, el sistema inmunológico y algunos aspectos genéticos en el producto, así como sus posibles expresiones en las diferentes etapas de la vida del niño. ¿Los padres de familia y los pediatras deben permitir que, además de las dificultades actuales que enfrentan hijos y pacientes, se agregue otro riesgo, como es la asequibilidad de la marihuana?
A reflection on whether to expose, determine and clarify the effects of marijuana on pregnant adolescents and their fetus is a determining factor to consider more judiciously the tendency to legalize marijuana in Mexico. We emphasize alterations in the central nervous system, immune system and some genetic aspects of the fetus and its potential expressions at different stages of a child’s life.
Should pediatricians and parents allow, in addition to the difficulties that their patients and children face today, the risk that is the affordability of marijuana? That is the challenge to overcome.
The everyday life of Mexican children and adolescents is becoming more complicated. This is a consequence of several factors including the high cost of basic services, both parents working, difficulty in choosing a suitable school, not having accessible recreational and sports areas, and technological progress which, misdirected, can offer more risks than benefits. To this is added the wide diffusion, in print and electronic media, that has been given to issues such as environmental, social and family violence, addictions and the easy availability of “licit” and “illicit” substances.1
In recent years, marijuana has gained importance due to its therapeutic effects aimed at very specific medical situations and, based on these conditions, has raised the possibility of its legalization. However, the supposed medicinal properties of marijuana have been the subject of a background investigation as well as part of various debates. Some researchers have confirmed that Cannabis contains active ingredients with therapeutic potential to control pain and nausea in cancer patients, stimulate appetite, and reduce eye pressure, among others. This justifies the implementation of new clinical studies to confirm its usefulness.2,3
Marijuana is a drug classified as “unlawful” and therefore banned in many countries. However, its consumption by teenagers and young adults is known since many decades ago and has probably increased since the second half of the last century to the present time.4-8
Cannabis sativa, or marijuana, has tetrahydrocannabinol (THC) as an active compound, which affects the regulation of emotions, memory, attention and attention control. The intense use of marijuana increases the likelihood of symptoms of psychotic, depressive and suicidal behavior. Available scientific evidence indicates that cognitive impairments produced by this drug may be reversible once the person stops using it, but other studies show that heavy marijuana use during adolescence can cause persistent changes.9,10
In the 1970s an extensive review on the knowledge of a number of illegal substances including marijuana was published.11 Current revisions performed by a group of professionals from the “Reflection Group on Addictions” in the Coordination of the National Institutes of Health and High Specialty Hospitals of the Ministry of Health set the tone for the following clarifications.12
Generally, over time, the toxic effects of marijuana have been less marked and, in general, the drug has been basically considered as a springboard to other substances.2 However, as pediatricians, it is imperative to know, point out and emphasize to adolescents and parents that there are three key situations where the risks of marijuana consumption can be very harmful13:
1. When consumed by a pregnant teenager
2. When young persons are exposed to drugs at an age at which the central nervous system is not yet fully developed
3. When consumption of marijuana cannot contain the effects of the emotional, social or economic conditions that led to its consumption14
In any pediatric situation, some basic knowledge of the behavior of experimental animals exposed to this drug should be taken into account along with its effects on the physical and emotional development of children and young persons.
It is known that intraperitoneal administration of C-tetrahydrocannabinol in rats tends to be distributed after 90 min in various tissues, mainly in the liver, kidney and testicles.15
The damage that this drug may cause in humans depends on the amount consumed, the product quality, and the frequency and duration of use, all coupled with the age of the consumer.16-18
The first situation, when the girl is pregnant, is the time that general practitioners and pediatricians can intervene. It must be remembered that tetrahydrocannabinol, marijuana’s active ingredient, can cross the placental barrier and therefore damage the developing fetus.
Depending on the stage of pregnancy when the exposure occurs, harmful effects can be considered. If it happens during the first 3 months, it has been reported that the drug causes a decrease in fetal testosterone levels during the period of sexual differentiation.17 If it occurs during the following trimesters, a delay in physical growth of the fetus and teratogenic damage to the brain affecting neurological development have been reported, expressed as a significant decrease in head circumference at birth along with depres sion, anxiety, memory problems, and attention deficit hyperactivity disorder (ADHD) in childhood and adolescence, including delinquency in adolescence but not in adulthood.12,18,19
It must be considered that usually the mother is not only exposed to marijuana but also the consumption of tobacco and alcohol. Smoking negatively altered fetal growth, although it appears that the effect of marijuana in regard to this aspect is often more severe than tobacco.12,20
The second possibility of risk occurs during puberty and adolescence, periods of life during which maturation of the central nervous system (CNS) is critical. Scientific evidence indicates that the earlier the exposure to drugs, the possibility increases that some brain regions become damaged. Several authors have pointed out that neurogenesis, myelination, migration of neuroblasts and glioblasts, the junction between neurons and maturation of neurotransmitter systems are altered, basic conditions for the proper functioning of the CNS. This may result in that the individual’s neuropsychological health may not recover in months, even though consumption is suspended.21,22 It is pertinent to mention that neuronal susceptibility in this period of life varies from one individual to another.
Other alterations described are the development of gynecomastia and decreased circulating levels of testosterone if the use of marijuana is chronic (although these are normalized after stopping consumption). In males, consumption can result in decreased spermatogenesis and sexual impotence. If exposure occurs during the prepubertal age, it may delay the onset of puberty.17
Kolansky and Moore offer a tentative classification of alterations that can occur in the CNS23:
• Biochemical changes: seen in persons in whom the infrequent use of Cannabis is proven and have a remission of symptoms 6 months after stopping the drug
• Biochemicalchanges with suspected structural change: this situation indicates chronic Cannabis use. After 6 to 9 months of stopping of drug consumption, partial remission of neurological changes is observed.
• Biochemical changes with possible structural change: these occur in persons who chronically use marijuana. After drug consumption is stopped, alterations take >9 months to disappear.
The possibility of addiction can occur as a result of prolonged use. The risk is greatest for those who begin consumption during adolescence when the brain has not yet fully matured. Moreover, lung and heart damage and head and neck neoplasms are situations that have been reported and that may be presented.2,24
The third condition occurs when, despite the frequent use of marijuana, the needs of the individual are not met so they try more addictive and dangerous substances. Although not all individuals are at risk to start this behavior, it is important to consider family, environmental and social factors that increase a person’s vulnerability and the absence of protective factors. In this sense, it is convenient to mention what is now known as “cumulative social adversity”, which includes domestic violence, violence against children and food or home insecurity.25 In our environment it is clear that after tobacco and alcohol, marijuana is the drug of choice among teenagers and young adults.26
The consequences outlined above generally depend on the following factors: amount consumed, frequency, duration and age of first use. During adolescence and young adulthood, the brain continues to mature. Some consequences of structural and functional brain damage can cause, among other effects, that the users have fewer years of education compared to non-users and, therefore, are less likely to complete their studies as well as having a greater chance of being exposed to social, school, domestic or environmental violence.
In adolescents, other alterations that have been associated with the consumption of marijuana are depression, anxiety, suicidal thoughts and personality disorders. One of the most cited links, although still controversial, is the lack of motivation, known as “amotivational syndrome.” This is defined as a decrease or lack of interest in participating in typically rewarding activities. Due to the role of the endocannabinoid system in mood regulation, these associations need to be confirmed and clearly understood in order to accept them.27,28
Finally, it is likely that there were some Mexican parents who had contact with marijuana at some time during their lives and apparently reported not experiencing any consequences. They note that they did not suffer any impact in regard to their life plan, but it cannot be said whether they may have achieved better academic, economic and social levels if they had not consumed marijuana. However, the current question would be: would you, parents or pediatricians, authorize or encourage your children or patients to consume marijuana, despite the harmful effects known so far?
What would be the purpose of allowing a situation that probably would encourage the acquisition of any other addiction or, as already mentioned, exposure of a being who is not yet born to injury and the possibility of becoming addicted to marijuana, to be in contact with more harmful drugs and thwart a more satisfying life projection for him/ herself and family?
Obviously, the Mexican government, like many countries, has focused on considering and analyzing the benefits or harm of legalizing marijuana. In this sense, the principal approach addresses and studies the impacts that legalizing production, marketing and consumption of illicit drugs would have on the country in order to have technical arguments that allow to establish their legal, political, social and economic viability. However, they have not taken into account the harmful effects on the pediatric population as described in this and other works.4-6
This is the challenge that parents and pediatricians must confront with their children and their patients, despite efforts made by officials or others, most likely for economic or political interests, in trying to legalize this drug and that obviously the health of future generations of Mexicans do not care.
Are we satisfied with the current reality? Do we need to implement other public policies to confront and stop this problem? Why do we not work in a timely manner and focus on prevention? If we do not act now, there is a risk that new generations will indicate that the current generation did nothing to prevent this.
Conflict of interest
The authors declare no conflict of interest of any nature.
Received 10 February 2014;
accepted 3 June 2014
* Corresponding author.
E-mail:cainm_inp@hotmail.com (A. Loredo Abdalá).