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Cannabis Use Can Lower Teenage IQs? - It's High Time We Take This Seriously

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The news was full of the story: Cannabis Use Lowers IQs. There were a myriad of reactions, everyone had something to say, and as expected, there was a polarised discussion as a result of the study.

The report in question, a 40 year longitudinal study, showed that cannabis use is almost certainly not good for developing minds and can have an adverse effect on adolescent IQs. Of course, any substance use is probably not conducive to a healthy child or their cognitive abilities. An abstinent teenager is preferable, and it's fairly common sense that we need to protect, educate and give every emplacement possible to the preservation of a child's development - we must deter all substance use.

The study - which can be read here - has of course been widely reported, but, there are a few underplayed aspects that we must address. The report has been welcomed by all sides of the 'cannabis debate' -- one of the key findings of the report is that those who start using cannabis in adult life have little ill effect; the study's author, Professor Terrie Moffitt from the Institute of Psychiatry, said:

It's such a special study that I'm fairly confident that cannabis is safe for over-18 brains, but risky for under-18 brains.

This is a significant finding given that our current drug laws are wholly tailored as a penumbra of protection towards our youth; and this is where the debate gets muddy: those who have chosen to use cannabis as an adult still suffer the punitive consequences of a lengthy prison sentence owing to their preferred substance which carries significantly less risk and harms than alcohol. A recent harm scale study that was released in the British Medical Journal rated cannabis as the least harmful substance with alcohol assessed as the fourth most harmful after heroin, crack and crystalmeth. Of course, no one will advocate that cannabis is harmless, but a comparative and contextualised discussion on harms are a necessity to any credible discourse.

It's hard to write on the contestable nature of cannabis without sounding like an aimless defender of the substance itself, but there are actually serious consequences to the flippant way that the UK media handles the scientific reporting of drugs, and specifically, cannabis. For far too long, we've dealt our national hand with a vigorous intent to scaremonger so as to dissuade children from the indulgences of cannabis use, as a result, we've become scientifically illiterate, not to mention apathetic, to realities of drugs. What we'd like to believe is not always the actuality.

The media's handling of such studies often serve to prop up failed policies and ideologies, but as this recent study shows, we're right to be wary where children are concerned, but we now have to address whether current laws are ethical.

Is the trawler net of prohibition - that aims to control the actions of adults and children alike - a correct way to prevent teenage usage? Do we tailor any other policy in such a primeval manner -- to protect our children, we must severely punish all adults? Does this style of punitive policy work as the deterrent that it's intended to be? There is a basic lesson in psychology called Reactance Theory - this theory certainly argues a case against trying to prohibit one's actions; giving an arbitrary cachet of 'illegal' to teenagers plays more than a part in the current prevalence of cannabis use in the UK. The Netherlands has a more regulated approach to their cannabis market, and they have a significantly higher age of first use than we have in the UK.

This recent study's findings drew the attention of Professor of Criminology at the University of Kent, Professor Alex Stevens, who made some pertinent observations on twitter:

"Interesting things about the Dunedin study on neuropsychological decline among cannabis users:

1. The effect on IQ is so marked. 2. That it was seen among cannabis *dependent* users 3. That it was not seen in adult onset users.....

4. That the highest IQ group was people who had used but not been dependent. 5. "data cannot definitively test whether effect is causal""

It's aspects like this that any good scientific news report should highlight, but alas, no. Not a single mainstream news site came close to delving this deep and opted for a more polarising angle.

Eager to know what an advocacy group made of the report, I contacted Norml UK - The National Organisation for the Reform of Marijuana Laws UK:

We welcome the report confirming what we always feared and suspected. It provides further evidence that prohibition has and will fail to protect the most vulnerable and youngest in society. It is high time to regulate cannabis as we do alcohol and tobacco, which also pose grave threats to young people's development. The study's author confirms that adult use of cannabis is relatively safe. Another study out of the University of Colorado shows that well regulated dispensaries, which allow adults safe access to medicinal cannabis, do not increase teen drug use. This clearly shows the necessity of proactive cannabis regulation


Norml UK allude to caveats that were also not addressed in the reporting of the study: as it stands, the cannabis market is largely comprised of feral pseudo-control. The black-market produces dire quality 'street weed' or 'soapbar' that's comprised of a hastily harvested product, with improper & immature THC/CBD balance, and can often be cut with other drugs for false potency, or adulterants such as diesel. Sold for profit motives - at any cost - this is the current lay of the land.

Barring a few exceptions, the current global cannabis market is as lowly and dangerous as it can get, we have reached the epitome of base level. No one is better placed to convey this than former Chief Constable, and now independent drug policy consultant, Mr Tom Lloyd:

Prohibition has artificially raised the price of cannabis and created a highly profitable criminal market resistant to policing efforts that, although it may seem counter-intuitive, has actually increased availability to young people. Dealers don't ask for proof of age; a controlled and regulated system would. Education and honest information, not law enforcement, will help youngsters to avoid harm.

It's no wonder that the regulation of the cannabis industry is now a political issue and in some cases it's a vote winner. Many U.S states, Europe, and more prominently Uruguay are looking to regulate the cannabis industry so as to avoid the very problems that the recent study highlights. With increased awareness to the potential harms - and the severe lack of protection that current policies provide - it's now time we address regulatory frameworks seriously and try to make cannabis use solely for the adults; it's time everyone played their part in consensual responsibility.