The Cannabis Report

À umas semanas atrás visitei um amigo no estrangeiro que fuma regularmente marijuana. Descobrir que ele usava marijuana não foi nenhuma surpresa, aquilo que mais me surpreendeu foi a frequência com que o fazia. Daí ter-me preocupado um pouco. Falámos um bocado sobre esse assunto e, dado o meu campo ser o da bioquímica e neurociências, prometi investigar um pouco na literatura quando voltasse a Trondheim, sobre possíveis efeitos nocivos a curto e/ou longo prazo devido ao uso de estupefacientes canabinóides.

Deste modo escrevi aquilo que mais tarde os meus colegas chamaram "The cannabis report". A pesquisa que fiz foi muito superficial (demorou-me cerca de 1 dia, e não tive tempo para consultar muitas fontes, embora confie naquelas que pesquisei). O relatório que escrevi não se debruca sobre os efeitos da marijuana, mas sim sobre possíveis consequências e impacto a nível de saúde do indivíduo. Também convém sublinhar que os detalhes científicos acerca da accão bioquímica/psicotrópica desta classe de compostos estão escritas duma forma vaga, apressada,e, consequentemente, não estão totalmente correctos ao detalhe (não me interessava bombardear o meu amigo com palavrões técnicos, o mais importante para mim era fazer passar a mensagem). No geral, confio nas conclusões finais do meu relatório.

Perdoem-me os leitores por estar escrito em inglês. Por questões de carácter profissional, não tenho muito tempo disponível para efectuar a traducão ou aprofundar o meu estudo. Se alguém tem sugestões ou correccões, ficarei agradecido por os mandar. Convém afirmar também, que embora as minhas conclusões apontem para o uso de marijuana como relativamente pouco nocivo, não quero que ninguém daí conclua que eu promova, aconselhe ou use pessoalmente este tipo de estupefacientes (prefiro restringir-me ao álcool como substância recreativa). Na minha opiniao, o melhor é permanecer sóbrio, dar umas corridas na floresta, apanhar uns banhos de sol na praia e levar umas garotas para casa de vez em quando (de preferência sempre a mesma, se possível!). Acredito que as substâncias neurotrópicos que existem no nosso sistema nervoso são suficientes para induzir os nossos "highs" naturais sem ter de recorrer a estimulantes químicos externos.

Ora aqui vai:

"In the last two days I have been researching a bit on the internet and getting some literature and discussing with a couple of the biologists in my lab about the possible side-effects of cannabis. I must warn that this is a superficial overview of the literature I got hold of and that it is not a full scale survey of the references I have read. But the conclusions are as follow:

- Marijuana works both in the peripheric and the central nervous system through the activation of two metabotropic receptors that have been identified in the early 1990´s. These ones are sensitive to an internal regulatory neurotransmitter called anandamide and the cannabinoid family of receptors is 10 times more frequent to find than the opioid system. Both share the property of balancing the effects of the dopaminergic system (potentiating its release). The receptors are more or less widespread everywhere in the nervous system. There is also a second class of cannabinoid receptors present at immunocells and they regulate the inflammatory reaction (by suppressing it to a certain extent). The effects of the cannabinoid substances are therefore generally unspecific.

- Cannabinoid is one of recreational drugs with less capability of leading to physiological addiction. Alcohol and nicotine are much stronger addictive substances than marijuana. Nevertheless, it can lead easily to psychological addiction (there is a difference between physiological and psychological addiction: in the first, a person feels bad and feels a strong need for the substance when some time has passed after the last dose; in the second, a person don´t feel this need, but in a way misses the feeling of being high – it is difficult to explain, but there is a difference).

- There is only one case of dying by overdose in the clinical records, and it was a guy who smoked around 6 joints a day for several months. The basic principle is that it is not possible to die of overdose of marijuana by smoking acutely (in just one episode), but it is possible to get poisoned by long-term consumption (although, as I wrote, there is only one proved case of it in the history of medicine worldwide).

- Although the risk of addiction is low, it can happen. There are withdrawal symptoms like insomnia, restlessness, lost of appetite, irritability, anger, jerkiness and increased aggression. Frequent use also leads to metabolical habituation: the user needs bigger doses to get the same effect.

- The effect of a dose lasts from 1 to 4 hours. The effects are gone the day after use. Nevertheless, since the cannabinoids are liposoluble substances, they have a very low exit rate from the body and they can be detected in human tissue up to one month after its use.

- Among the most prominent psychotropic effects at the cognitive function level, loss of working memory and decreased ability to concentrate are the best known. This is the reason people are advised not to work, drive or do precision work while smoking marijuana. From what it is known, these effects are gone the day after.

- High doses of marijuana consumption also affect reproductive success, especially in men. It decreases sperm mobility and it interferes in the fertilization process. But it needs to be frequent users in order to get this impairment.

- The biggest health risks are the ones related with the smoking: lung and throat cancer, bronchitis, heart problems, etc. But that is mainly derived by the fact that one has to smoke it, so it has the same risks as smoking normal tobacco. It hasn´t be proven any neurodegenerative implications yet (Alzheimer, Parkinson, etc). Actually, there are lines of research were people are testing it as medicine to these same diseases. Cannabinoids induces lower immune resistance (you become less resistant to colds, for example), but it seems to have therapeutical effects by reducing the inflammatory responses or in treatment of chronic pain.

- There is some correlation between schizophrenia and cannabis use, but there is debate about it. Some experts argue that cannabis use is not a cause, but people prone to schizophrenia may use it more.

- It has been discussed about cannabis being a “gateway drug” to heavier drugs. Research so far has shown that animals exposed to cannbinoids need higher doses of opioids in order to get the same effect. Another issue is the sociological aspect: since it use is illegal in most countries, the sort of environment where one gets cannabinoids is the same where one gets heavier stuff.

- The last point of this list is the one I found more curious. It seems that people who use cannabis often score lower in ambition and motivational tests. They are more prone to change careers and are less ambitious than the non-users. They do not score lower at intelligence or capacity tests, they are just less ambitious. They are also more prone to have doubts about their present career or life choices and have less defined long-term goals than the control groups. Again, researchers don not know if this is an effect of cannabis use or if it is a parallel effect: people who start using cannabis were already susceptible to see life in a more liberal way.

All in all, marijuana is not totally harmless to health, but it is less harmful than alcohol or tobacco. This is the main conclusion of my (short) study. As long as you don´t drive while high or use it very frequently, I don’t see major health risks associated with it. But, at a personal level, I wouldn´t like to see you becoming addicted to it (well, to the same extent as alcohol or tobacco as well)."

Trondheim, 10 de Agosto de 2006.