Cannabis smoking 'permanently lowers IQ'

[Silent_Bob]

http://www.telegraph.co.uk/health/healthnews/9426205/Cannabis-smoking-permanently-lowers-IQ.html

Researchers found persistent users of the drug, who started smoking it at school, had lower IQ scores as adults.

They were also significantly more likely to have attention and memory problems in later life, than their peers who abstained.

Furthermore, those who started as teenagers and used it heavily, but quit as adults, did not regain their full mental powers, found academics at King's College London and Duke University in the US.

They looked at data from over 1,000 people from Dunedin in New Zealand, who have been followed through their lives since being born in 1972 or 1973.

Participants were asked about cannabis usage when they were 18, 21, 26, 32 and 38. Their IQ was tested at 13 and 38. In addition, each nominated a close friend or family member, who was asked about attention and memory problems.



About one in 20 admitted to starting cannabis use before the age of 18, while a further one in 10 took up the habit in the early or mid 20s.

Professor Terrie Moffitt, of KCL's Institute of Psychiatry, who contributed to the study, published in the journal Proceedings of the National Academy of Sciences, said "persistent users" who started as teenagers suffered a drop of eight IQ points at the age of 38, compared to when they were 13.

Persistent users meant those who used it during at least three of the ages from 18 to 38, and who said at each occasion they were smoking it on at least four days a week.

She said: "Adolescent-onset cannabis users, but not adult-onset cannabis users, showed marked IQ decline from childhood to adulthood.

"For example, individuals who started using cannabis in adolescence and used it for years thereafter showed an average eight-point IQ decline.

"Quitting or reducing cannabis use did not appear to fully restore intellectual functioning among adolescent-onset former persistent cannabis users," she said.

Although eight points did not sound much, it was not trivial, she warned.

It meant that an average person dropped far down the intelligence rankings, so that instead of 50 per cent of the population being more intelligent than them, 71 per cent were.

"Research has shown that IQ is a strong determinant of a person's access to a college education, their lifelong total income, their access to a good job, their performance on the job, their tendency to develop heart disease, Alzheimer's disease, and even early death," she said.

"Individuals who lose eight IQ points in their teens and 20s may be disadvantaged, relative to their same-age peers, in most of the important aspects of life and for years to come."

The cognitive abilities of the 10 per cent of people who started in their 20s - who could loosely be classed as college smokers - also suffered while they were still smoking.

However, if they gave up at least a year before their IQ test at 38, their intelligence recovered, suggesting their brains were more resilient and bounced back.

Prof Moffitt said adolescent brains appeared "more vulnerable to damage and disruption" from cannabis than those of fully mature adults.

Reliable figures on cannabis usage among today's British teens and twentysomethings are hard to come by.

But Prof Moffitt said there was growing concern in the US that cannabis was increasingly being seen as a safe alternative to tobacco.

"This is the first year that more secondary school students in the US are using cannabis than tobacco, according to the Monitoring the Future project at the University of Michigan," she noted.

"Fewer now think cannabis is damaging than tobacco. But cannabis is harmful for the very young."

[WithoutAPaddle]

Does this message board's software still support youtube video links?

Update: I devised a "work around".  I find a youtube video I want to post, and I blow it up to full-screen by clicking the "pop out" utility, and I make that my "[u r l =http://_____] destination.  Then, within the URL brackets, where one would normally put the typed, hyperlink heading, I instead insert a suitable image using [img] bracketing.  I can either import an image that is relevant, or I can obtain a thumbnail version of the youtube opening screen shot by searching youtube for the formal title of the video, and then "viewing" the thumbnail that accompanies the index link to that video.

But I'd still prefer to use the full-sized image rather than the thumbnail, if anyone knows how I could do that...

[Free libertarian]

As soon as I recover from my hangover and have a cigarette I will post a retort to this fallacious report.

[WithoutAPaddle]

http://www.telegraph.co.uk/health/healthnews/9426205/Cannabis-smoking-permanently-lowers-IQ.html...

Author bio info:

Stephen Adams
Stephen Adams is The Daily Telegraph's Medical Correspondent. He joined the paper in 2007 and has previously covered arts and general news.

Well, that inspires confidence.  Last year, in another forum, one regular poster espoused a novel economic theory and when he furnished a link to the source material, I found that the author was a 30 year old "blogger" who, after earning a Bachelors in Liberal Arts, had worked for one year as a social worker and three years as a fitness instructor.

"Fewer now think cannabis is damaging than tobacco."

It wouldn't take much work for Author Adams or anyone else to turn that word string into a sentence.

[MaineShark]

Eh... it's entirely possible that taking drugs during adolescence can impair brain development.

But this isn't typically a question of "cannabis or nothing."  A better comparison might be how much damage is done by cannabis, versus alcohol, versus Ritalin, versus tobacco, versus antidepressants, versus etc. etc. etc.

A wide variety of chemicals can cause problems if taken in large quantities by adolescents, because their brains are developing.  I would be shocked if many kids who are being drugged for "behavior problems" in school, aren't being given chemicals that are far more dangerous than cannabis.

Yeah, kids probably shouldn't smoke cannabis.  But in the real world, kids will take a variety of substances.  It's probably much more important to consider situations in which they are being ordered to take a substance on a daily basis, than ones they are occasionally taking for recreational purposes.

[lildog]

But this isn't typically a question of "cannabis or nothing."  A better comparison might be how much damage is done by cannabis, versus alcohol, versus Ritalin, versus tobacco, versus antidepressants, versus etc. etc. etc.

Very good point.

Additionally this study implies that without cannabis the cross section of people who they studied actually would have been in the 50% mark of IQs.

Typically I've found more often then not those people who are open about drug use are not the brightest bulbs to begin with.  And those who keep it quite usually are those who are more successful in careers etc.  Most professionals (those with higher HQs would tend to fall into this group) would not openly admit to using any forms of drugs because of the chances this could harm their careers.