Posted on 12/18/2011 5:35:00 PM PST by Tarantulas
Brain abnormalities that make teenagers more likely to smoke cannabis have been identified for the first time by Australian scientists.
Their study of more than 100 Melbourne teens also confirmed that cannabis harms the brain, adding weight to a raft of previous research on damage caused by long-term use of the drug.
Researchers from Monash and Melbourne universities took high-tech images of the brains of 155 primary school students when they were 12.
Four years later when they reached their milestone 16th birthday, the students were asked whether they had used cannabis.
Of 121 who responded, 28 admitted to using the drug.
When the researchers checked the scans taken when those students were 12, they found a part of the frontal lobe area in their brains was smaller than those in teens who steered clear of cannabis.
Lead researcher Professor Lubman, of Monash University, said the students with abnormalities in the orbitofrontal cortex - the brain region involved in memory, reward and decision making - were more prone to using cannabis.
"What we found is that only the orbitofrontal cortex predicted later cannabis use, suggesting that this particular part of the frontal lobe increases an adolescent's vulnerability to cannabis use," he said.
"However we also found no differences in brain volume in other parts of the brain that we have shown to be abnormal in long-term heavy cannabis users, confirming for the first time, that cannabis use is neurotoxic to these brain areas in humans."
Previous studies have shown that long-term heavy cannabis use harms the brain.
Adolescent users have been found to have difficulties with paying attention, solving problems and with their memory.
However the study is the first to examine whether existing brain abnormalities have a role in whether teens start using cannabis.
It was published online by the journal Biological Psychiatry.
Neither which should matter to adults of legal age.
When I was in High School, I remember a conversation (or more accurately an attempted conversation) I had with a stoner while riding the bus to school. That was all it took for me to steer clear of the stuff. I knew I never wanted to look or sound like that kid!
When I was in High School, I remember a conversation (or more accurately an attempted conversation) I had with a stoner while riding the bus to school. That was all it took for me to steer clear of the stuff. I knew I never wanted to look or sound like that kid!
"I just want to sit on my back porch, not bother nobody and give myself a lobotomy" - /Libertarian mode off
"I just want to sit on my back porch, not bother nobody and give myself a lobotomy" - /Libertarian mode off
Got to admit that during my graduate classes in NeuroPsychology and Statistical Method I didn't ever encounter a 600% chance of anything, WTH does that mean?
Occupoopers prove the rule.
What it means, Steve, is that smoking pot when you’re a teenager and your brain is still developing, ain’t good for your brain, period.
The Herald-Sun’s article is so poorly written I can’t make heads or tails of it, except (I think) for the part about the abnormal orbitofrontal cortex predicting later Cannabis use. The word “Changes” in the title is completely inappropriate. The article is not mainly about changes, it is about existing abnormality predicting later cannabis use. The remainder of the description is indecipherable. It seems to describe anatomical effects of use, but is unclear. Unfortunately legions of FReepers seem to think they understand the article.
I think the guy who wrote it was stoned.
Mel
My sister used to be a police officer, and she said she could usually guess at what age someone started smoking dope, because it seemed their mental development was arrested at that point.
I was very young in the 70’s after pot had taken it’s toll on my older brother’s friends. He went to Viet Nam. Memory and ambition were not assets they suffered from. My brother made it a point to give me a tour of the wreckage.
The problem with legalizing drugs, is that dummies like you will promote the use of those drugs to dummies who don’t know any better. Then people like me will have to support them because they are too brain and soul fried to support their own babies.
I despise the war on drugs. Just trying to figure out how we can permit idiots to fry their own bodies and brains without them bothering everyone else with their mental problems on the job and their upkeep.
Placemark to insert my solution tomorrow!
heheh
Fr_freak,
I agree with everything you said and thanks for your service.
You have to kind of read between the lines to understand it. Maybe the author smoked too used too much cannabis when a teen.
Orbitofrontal Volumes in Early Adolescence Predict Initiation of Cannabis Use: A 4-Year Longitudinal and Prospective Study.
Cheetham A, Allen NB, Whittle S, Simmons J, Yücel M, Lubman DI.
Orygen Youth Health Research Centre, Centre for Youth Mental Health, University of Melbourne, Parkville, Victoria, Australia.
Abstract
BACKGROUND:
There is growing evidence that long-term, heavy cannabis use is associated with alterations in regional brain volumes. Although these changes are frequently attributed to the neurotoxic effects of cannabis, it is possible that some abnormalities might predate use and represent markers of vulnerability. To date, no studies have examined whether structural brain abnormalities are present before the onset of cannabis use. This study aims to determine whether adolescents who have initiated cannabis use early (i.e., before age 17 years) show premorbid structural abnormalities in the amygdala, hippocampus, orbitofrontal cortex, and anterior cingulate cortex.
METHODS:
Participants (n = 121) were recruited from primary schools in Melbourne, Australia, as part of a larger study examining adolescent emotional development. Participants underwent structural magnetic resonance imaging at age 12 years and were assessed for cannabis use 4 years later, at age 16 years. At the follow-up assessment, 28 participants had commenced using cannabis (16 female subjects [57%]), and 93 had not (43 female subjects [46%]).
RESULTS:
Smaller orbitofrontal cortex volumes at age 12 years predicted initiation of cannabis use by age 16 years. The volumes of other regions (amygdala, hippocampus, and anterior cingulate cortex) did not predict later cannabis use.
CONCLUSIONS:
These findings suggest that structural abnormalities in the orbitofrontal cortex might contribute to risk for cannabis exposure. Although the results have important implications for understanding neurobiological predictors of cannabis use, further research is needed to understand their relationship with heavier patterns of use in adulthood as well as later abuse of other substances.
Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
http://www.ncbi.nlm.nih.gov/pubmed/22129756
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