Cannabis use linked to IQ loss

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Cannabis use linked to IQ loss

3News NZ

Cannabis has been linked to memory loss (file)

Cannabis has been linked to memory loss (file)

People who regularly use cannabis from their teens may suffer memory loss and a lower IQ by the time they reach their late 30s, an international study of 1000 people in Dunedin has found.

Watch the video to see the NZ Drug Foundation's Ross Bell speak to Firstline this morning.

The research published by the Proceedings of the National Academy of Sciences in the United States examined the decline in IQ and cognitive abilities by testing the Dunedin people, born in 1972/73, at age 13 and again at age 38.

Study members who regularly used cannabis showed a greater decline in IQ compared with other participants and their habit appeared to affect everyday cognitive functioning.

Regular use is defined as four times a week.

Teenage cannabis users tended to become regular users and experienced a greater IQ decline compared with those who started using cannabis as adults.

Quitting or reducing cannabis use did not fully restore brain functioning among teenage cannabis users, and the researchers say cannabis use in adolescence, when the brain is developing, could have "neurotoxic effects".

The study was led by Madeline Meier of Duke University in North Carolina and included other researchers from the US, the United Kingdom and Otago University in Dunedin.

Commenting on the findings, Dr Simon Adamson, senior lecturer at Otago University's national addiction centre in Christchurch, says the magnitude of cognitive decline from heavy regular cannabis use is of real concern.

"Clearly we must focus energy on reducing the prevalence of cannabis use in adolescence," he said.

Robin Murray, professor of psychiatric research at King's College London, says it's "part of folk-lore among young people that some heavy users of cannabis ...seem to gradually lose their abilities and end up achieving much less than one would have anticipated".

"This study provides one explanation as to why this might be the case," he said.

But the study did not address the type of cannabis used.

"We now know that use of high potency types of cannabis (called skunk in the UK) appears to be more likely to cause problems," he said.

NZN

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Comments

9/01/2013 11:54:59 p.m.

am wrote:

Watching Fox News channel causes loss of IQ. Rupert Murdoch is an illegal drug.

21/09/2012 4:32:34 p.m.

Hackney MAN-DEM, London E5 wrote:

kEEP DRUGS ILLEGAL SO I DONT HAVE TO WORK by Raggy on July 11, 2010 at 07:22PM We should keep all drugs illegal so i dont have to work buy keeping drugs illegal i can make a good profit without leaving my flat. Once a week i have a man come to me with £10,000 of heroin, crack, lsd, coke and cannabis. Because no one can buy these at the shops i make a killing and dont have to pay taxes or go to work. Because it is illegal i dont have to ask kids for ID and to stretch my profit further i cut the products with things like washing powder, sometimes i put ground glass in my cannabis deals to make them weigh more! its great. i have to go to the social once every 2 weeks to get my JSA, thats a side income for me so i can afford my sky+ HD subscription and pay my merc repayments without cutting into my drug profits. if im arrested i MAY go to jail but never mind, ive saved a few hundread thou from over the years in an account not linked to me so while it costs millions to keep in jail im sitting back waiting for my release date, or what i call retirement day. Why the contribution is important it helps the gov hide under a smoke screen and removes mp's chances of being discraced for supporting the legalise movment. if you havent noticed im being facetious. the above is exactly what any drug dealer would say.

2/09/2012 11:11:13 a.m.

Mike wrote:

@Brendan Another dopehead claiming dope is beneficial.

Check Statisics NZ, is gives almost 4000 people hospitalised for drugs with almost 1/2 involving cannabis. To say that its not harmless is garbage. There is a definate obesity problem linked to cannabis, from the munchies side effect.

Any substance that impairs ability can be extremely danagerous. I dont want any drunk or stoner behind the wheel driving, or anywhere else that can cause harm.

What we need for driving is an impairmnet test, not just a alcohol test. If your reactions aren't up to par, you shouldn't be driving. Be it too much alcohol, drugs, or lack of sleep. Combine any of those in smaller amounts and what wont be enough to fail current tests can be a deadly mix, hence an impairment test checking reaction speeds is more likely to be a better representation than just a set level.

Dope kills braincells. Given.
Picking up the dope habbit? You would need to be brainless to start the habbit.

31/08/2012 8:27:05 a.m.

Brendan wrote:

Mike, Firstly learn to spell. Hospitalisation for cannabis use? You really are ignorant. Given all your arguments we should probably prohibit alcohol too: with it's impairment inducing qualities; cancer links; obesity links; countless motor-vehichle accidents and countless other social harms. It is actually possible to kill yourself from an alcohol overdose. Go figure. You can not do that with cannabis. Which one is legal? Hypocrisy? In reality cannabis use will never disappear. Currently it is an unregulated market (yes there is a market). Unregulated means a criminal market; people can get (and use) as much as they want which leads to the negative effects of cannabis use. Given it is far down the drug scale of harm (as opposed to heroin) a moderated use of it, once or twice a week and not too excess, is probably not that bad compared to what some of us eat or drink. Cannabis can also be a creative drug if used correctly. It expands your conscience, enhances visual and aural experiences, enlightens conversation, and yes, makes you question the status quo. That's why it's illegal. To keep people like you ignorant.

29/08/2012 9:08:39 a.m.

Mike wrote:

Science is about being able to repeat a result.

Someone is claiming that a study in the 60's showed dope was beneficial in mice for treating cancer. But back then there were also studies that showed it beneficial to smoke tabbacco! If dope is beneficial in treating cancer then I expect some study in the last 50 odd years to try to prove that and use it as a cancer drug. Even then, the downside of any drug can outweigh its use.

How much of todays obessity is linked to cannabis? Thats a link thats been shown in many studies. The munchies of use leads to over eating and obessity in many. All the problems of obessity as a side effect of cannabis use?

Inhaling any substance is bad. Be it smoke, or carbon fibre like F1 drivers have been found to have in their lungs.

Each year 1000's are hospitalised for drug use, and most of them are from cannabis. Now it may Dr Stoned feels hospitalisation for cannabis use is harmless. As is the personality disorders that cannabis unlocks.

Generally cannabis has way more downsides than benefits. Someone stoned driving can basically watch as an accident unfolds around them and still do nothing about it. So much of todays life requires no impairment, and cannabis impairs ability to think clearly, and reaction speeds.

Another study found over half of those tested after road accidents were on drugs, of which most were illegal drugs like cannabis, ie your more likely to have an accident on cannabis than without.

29/08/2012 8:38:18 a.m.

LondonRastaGeneral wrote:

and for those who stared in their twenties no problem at all. Simple. Legalisation and r18. now the legal age to purchase herb is 20 dollars. The healing of a nation.

28/08/2012 8:56:49 p.m.

the DR wrote:

big deal and huffing butane has killed at least 3 just in New Zealand in the last 6 months and no one has ever died from cannabis in the whole history of the entire world ever. just for those who wont the facts

28/08/2012 6:50:10 p.m.

bukster wrote:

We need to take this sort of "scientific" report with a grain of salt. It might be quite right and there is a danger. It could be little more than anti-drug nonsense. Part of the problem is that with all the hysteria surrounding this issue it is difficult to get factual, unbiased info on drug harm. If we teach kids rabid anti-drug rubbish in schools, the kids will soon work out that the info on cannabis is over-the-top nonsense. They might then conclude that the message on meth has a similar rate of exaggeration. Then they might really come unstuck if they try that.

28/08/2012 6:34:16 p.m.

Ben wrote:

These study's have been conducted to push a political propaganda. IQ is no measure of a persons value to society & hardly takes into consideration imagination & creativity. Cannabis is an amazing plant which can have many positive effects on users.

28/08/2012 6:31:06 p.m.

sue wrote:

Well, is this selection of people studied, at age 38, from the same study as THE QUEENS MARY SURVEY in Dunedin?