Teenagers who frequently smoke marijuana may be setting themselves up for declines in intelligence and mental function that persist well into adulthood, new research suggests.


In a decades-long study of more than 1,000 New Zealanders, researchers found that adolescents who used marijuana at least four days per week lost an average of eight IQ points between the ages of 13 and 38 -- a pattern not seen among people who began smoking heavily only in adulthood.

Heavy pot smokers tended to show deficits in memory, concentration, and overall brainpower in relation to their peers, but these problems were more pronounced -- and seemingly more lasting -- among those who picked up the habit as teens, the study found.
Individuals who smoked heavily in adolescence had consistently lower IQs at age 38, even if they'd cut back in the previous year. By contrast, the IQ of the relative latecomers to marijuana was more closely linked with how much pot they'd smoked recently.

"The effect of persistent cannabis use on intellectual functioning is really confined to adolescents, (which) suggests that adolescents, in particular, are vulnerable to the effect of cannabis," says lead author Madeline H. Meier, a psychologist and postdoctoral researcher at Duke University in Durham, North Carolina.


An eight-point decline in IQ isn't negligible, the authors say. Previous research suggests a drop in intelligence of that magnitude could, for instance, affect a person's long-term career prospects, job performance and income.
It's reasonable to suspect that still-growing teen brains might be especially sensitive to the cumulative effects of marijuana, says Dr. Jeffrey Brosco, a professor of pediatrics at the University of Miami's Miller School of Medicine.
"In the developing brain, neurons are growing and changing, synapses are forming," says Brosco, who was not involved in the study. "When there's a lot of change in any part of the body, particularly the brain, that usually means it's more vulnerable to environmental influences."





More at--http://edition.cnn.com/2012/08/27/health/health-teen-pot/index.html

The conclusion isn't very surprising I guess, but nice to have actual evidence to back it up.

Didn't read d article but d topic waiting for some marijuana addict to come render this article baseless

I guess so. . .especially if such a topic is posted in the 'political' section of NL.
Just saying. . . .

I have met MANY people who indulge in such a thing. . .YUP! They are all the DUMBEST! With mouths smelling like SHYTE!!!
Interesting to watch them have the fake air of confidence. . .to TOAST A WOMAN and act 'BRAVE' without all faculties intact. I love watchiing that 'dazed' look on their faces. Mu he he he he he he he. . . till it wears off. Back to their 'TIMID' shells.

Dumb arzzzes! But they sing AND PHOCK good tho. . .like BOB MARLEY!!!

Ì. Smoked it before to help me revise once and it helped. I remembered everything I read.

Hmm, really? Adderall and Ritalin have that effect. I wasn't aware that marijuana improved memory. All my friends who smoke a lot are very forgetful

Ozzy Osborne is proof enough

@ekt' lol, I'm forgetful in general so I guess it had the opposite effect on me.

lol

I heard about this just the other day.

Drugs are for the weak, IMO.

I concur being a former/rehabilitated smoker(that's for me)... However, I don't think this is the case for everyone, some people are different... I know people who function better after smoking zoobie, but personally - it makes me weak, forgetful, lazy, and at the same time overly assertive(the same for most of my mates)...

It depends on the individual's brain capacity and how much their brain can take... I've seen people smoke mash(the lightest marijuana) and go nuts - and I've also seen people smoke high grade, or cheese, yet maintain their normalcy but function at a higher IQ/consciousness(say things extremely intelligent and brilliant)...

In conclusion, just like every scientific research, I think this research is inconclusive!

You don't smoke mary J. Its nt for #non smokers#

Rubbish article....
Even sum agberos sharp pass d so called corporate class of ppl...
At least, LASTMA can't fool d agberos, but dey fool and extort from d 'educated' ones.
Hu dull, DULL, hu sharp, SHARP!

Hello everybody, please need advice on this issue. My wife just arrived America but incidentally had her passport stamped with NO E.O.S/ NO A.O.S by a lady immigration officer who went verbal with unprintable things said. Please is there any possible way in which she can get an extension with this stamped on her passport?

Na lie!!!!
Hav u eva tried smokin skonk(SK)?? I swear u‘ll b communin wif d gods

Abeg help me shout am 2 dia ears...marijuana is not d best thing 2 give inspiration except u wan turn 2 d likes of terry g,mallam spicy&co(i hope u know dat 2baba start makng sense when he quit egbo)

If they are likely to forget how come 2 of my friends (neighbours) who smoked weed during our University days manage to pass their exams in their respective departments? If you knew these dudes, you'd rephrase your topic because those guys came out with 2'1 (Honours).
I believe it depends on the purpose its bn smoked for (like they would say).

It is not always advisable for children to smoke weeds when their brain are not yet developed yet,unfortunately it is quite common in the west now for pre-teenagers/adults to be smoking not just weed but SKUNK which leaves them paranoid and agitated at all times.Weed is for matured brains and minds that can channel the effects for positive reflections and activities.

Weed is not for evil people,not for the naive and definitely not for children.

shymexx: I concur being a former/rehabilitated smoker(that's for me)... However, I don't think this is the case for everyone, some people are different... I know people who function better after smoking zoobie, but personally - it makes me weak, forgetful, lazy, and at the same time overly assertive(the same for most of my mates)...

It depends on the individual's brain capacity and how much their brain can take... I've seen people smoke mash(the lightest marijuana) and go nuts - and I've also seen people smoke high grade, or cheese, yet maintain their normalcy but function at a higher IQ/consciousness(say things extremely intelligent and brilliant)...

In conclusion, just like every scientific research, I think this research is inconclusive!

na wa o! see lecture.please which one do you advise i smoke? because i need am badly!

and i guess it increases the IQ of adults?

No wonder Lil Wayne's IQ is in the single digits. He's actually a very intelligent guy.

I tot dat marijuana gives inspiration

Marijuana dis marijuana dat.blah blah blah. Like sum1 said, it affects pple differently. As if say d so calld scientists no dey take am. All I hear abt is d bad side.make dem yarn abt d good sides na EWU scientists

shymexx: I concur being a former/rehabilitated smoker(that's for me)... However, I don't think this is the case for everyone, some people are different... I know people who function better after smoking zoobie, but personally - it makes me weak, forgetful, lazy, and at the same time overly assertive(the same for most of my mates)...

It depends on the individual's brain capacity and how much their brain can take... I've seen people smoke mash(the lightest marijuana) and go nuts - and I've also seen people smoke high grade, or cheese, yet maintain their normalcy but function at a higher IQ/consciousness(say things extremely intelligent and brilliant)...

In conclusion, just like every scientific research, I think this research is inconclusive!

You were smoking mari j before? Now I begin to understand your posts. My apologies, but I used to wonder at your level of reasoning. No insult intended, just the plain truth.
The title of this post is too mild. Smoking mari j doesn't reduce the IQ of teenagers. IT SENDS THEM TO YABA WHERE FEW RECOVER

Smoking weed is bad.. hmm okay

Now I understand why Seanet01 is a retarrd.

i like the way these dudes go hysterical after every shot of precious hashish . . . . . .keep it up guys.

@OP
Or perhaps it could mean that the reason they started smoking the marijuana in the first place was because they ALWAYS were retarrds?

ekt_bear: Hmm, really? Adderall and Ritalin have that effect. I wasn't aware that marijuana improved memory. All my friends who smoke a lot are very forgetful

It does. short term...it heightens perceptions. Long term...affects memory.

hmmm