The Impact of Cannabis on the brain

In 2006 an advert was produced and shown on TV in an attempt to discourage people from smoking cannabis. The ad featured customers in a futuristic ‘brain shop’ with the shop being stocked with brains all suffering from apparent chronic symptoms of cannabis use such as memory problems. The problem about adverts like this is that they don’t seem to be backed up with much sound reasoning in fact many studies have shown that the majority of the effects of cannabis are reversible even in long term users.


For instance the effects of long term heavy smoking of cannabis can last weeks or years but they do wear off this fact seems to be neglected by people who seem to label it cannabis as dangerous even with just one use. For instance research done at Harvard found revealed that even with heavy smokers who smoked pot daily after 28 days of not using it they managed to get the same score on cognitive tests as those who have never smoked cannabis in their life. As the research author notes the long term effects of long term cannabis on the brain compared to alcohol are favourable. Long term use of alcohol will affect the user for a far longer time span than cannabis.


The latest study by the University of Melbourne seems to take another view on how the stereotyping of cannabis causing memory problems came about. Instead of just looking at the effects cannabis has on the brain the study looked at the education of the subjects and their gender. The idea behind it was that perhaps those who smoked pot were in general males and had a lower level of education than a non pot smoker. Many previous studies had extensively used verbal intelligence tests which statistically women generally do better at than men and combined with the hypothesis that cannabis smokers had a lower level of education the researchers put forward the notion that factors such as these accounted for lower levels of intelligence in cannabis smokers.


The study by the University of Melbourne concluded that only in the immediate recall test was there any difference in those who did not smoke and those who did. They also concluded that the effects of marijuana on cognitive functions were completely reversible after taking pre-existing factors into account. As the paper says “the adverse impacts of cannabis use on cognitive functions either appear to be related to pre-existing factors or are reversible”.


The fact that the age of first use of cannabis was dropped  by the researchers because there was no significance or link between age of first use and cognitive impact also shows that the long term use does not seem to increase damage to cognitive functions. This is quite different from the legal substances such as alcohol where it has long been known that “excessive use can cause structural and functional abnormalities of the brain”. This includes Cerebral Atrophy and damage to the frontal brain systems so why is it that there is such a big emphasis on the damages of the use of cannabis yet when it comes to alcohol the dangers are emphasized less.


Adverts which focus about warning about the dangers of alcohol merely focus on the dangers of drinking too much yet when it comes to marijuana there is more of an emphasis on highlighting a mythical danger of even a low dosages of cannabis. Adverts about marijuana will not say that ‘you should not overdose on marijuana’ but instead focus on a ‘you should not smoke it full stop’ type of attitude. Why is it that a drug that killed over 8000 people in the UK in 2009 is legal, yet cannabis which was only officially linked to 12 deaths in the UK in 2007 is somehow epitomized as some deadly brain manipulating drug?  The fact that the alcohol is allowed to be distributed free to the public in supermarkets whilst cannabis is banned because of it being thought of as dangerous and of no use is ludicrous and reeks of double standards. How can it be right that a drug that causes 8000 deaths can be sold next to necessities like food but cannabis a drug which is relatively safe to alcohol is banished into the black market.


What is more dangerous is that this scaremongering through propaganda styled ads is very harmful. It tarnishes legitimate research and prevents the real dangers from being discussed. These ads focus primarily on trying to scare people from using cannabis instead of teaching them about the dangers especially. They should be more about educating people about the effects of cannabis such as distorted perception, trouble thinking and loss of coordination.


Sometimes the effects of cannabis can even positively impact parts of the brain such as semantic memory function where those who were currently high on cannabis were compared with those who have never smoked cannabis. The results showed that cannabis uses showed increases in automatic semantic priming this is where one word allows you to react to another word quicker for instance the word dog may lead to a decreased reaction time for the word wolf. This may seem like something quite irrelevant but it also shows that the impact to the brain is not all negative.


No one is suggesting that there are no acute impacts on cognitive functions but instead adverts like the one done in 2006 paint a picture of irreversible harm on cognitive functions. When the reality is that the damages done by cannabis is relatively minimal compared to alcohol where there is a high chance of the effects  of alcohol having a far longer negative impact on the human brain and creating more severe withdrawn symptoms than cannabis.


The studies point to cannabis not being as dangerous as the advert first proposed and indeed it seems quite amazing the difference in how governments treat both alcohol and cannabis with one being outlawed because of some out of date belief that it is somehow bad whilst the other is sold in shops legally. Look at America where alcohol is freely brought yet cannabis is somehow shunned upon with the DEA saying there is ‘no medical use of marijuana’ does alcohol has a medical use? Why is it that alcohol which causes way more death on average than cannabis is for some unexplained, unknown reason allowed yet cannabis which is relatively safe is somehow banned? The way governments around the world treat cannabis is hypocritical, unscientific and ineffective its time the research being done is taken seriously instead of being ignored by governments.