Marijuana Use Shrinks Teenagers' Brains

[t-pain]

found a video on this.

 

http://www.nlm.nih.gov/medlineplus/videos/news/Marijuana_121613-1.html

 

resto and others have a point, there are many variables that can shrink a persons brain.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2689675/

"Decreased Brain Volume in Adults with Childhood Lead Exposure"

 

alcohol drank by teens or alcohol drank by pregnant mothers , or tobbacco smoked by pregnant mothers can also affect the childrens brain size.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2631356/

 

i really want to read the study on this one. anyone got it ? 97 teenagers total sample size?

 

heres the thread for the previous brain abnormalities mri imaging study

http://michiganmedicalmarijuana.org/topic/46283-study-finds-recreational-cannabis-use-is-associated-with-abnormalities-in-the-brain/

Edited August 11, 2014 by t-pain

[FranksHotPeppersAndMarijuana]

Yes but I would guess that one of the parameters of the study was to rule out or in uses of other substances with ttesting as well as examining other lifestyle choices. Not to mention when you are conducting a study like that it is usually double blind so that the participants didn't know what was being studied. So it would seem odd that a teen would admit to using one substance but not others.

[t-pain]

interesting reply to the april study

 

Nidia J. Melendez, Research Assistant
Columbia University

I read with great interest the report by Gilman et al. (2014) examining the effects of recreational marijuana use by young adults. The authors concluded that brain regions implicated in reward and drug addiction behavior, i.e., the nucleus accumbens and amygdala "...revealed greater density values in marijuana users than in control participants." After comparing MRI brain scans of casual users to those of controls, researchers speculated that regional differences were abnormalities caused by cannabis use that attribute to drug addiction. While this is an intriguing interpretation, I feel at least two points deserve further discussion.

First, there were no measures of cognitive performance or any other behaviors in the current report. This makes it nearly impossible to interpret the meaning of any brain measure differences. As Di Domenico and Eaton (1988) pointed out in their classic paper, "Without a quantifiable concept of behavior we run the risk of performing neurophysiological experiments that have no behavioral correlates but which entice us to make unwarranted speculations without the neural basis of behavior." As a result, causal explanations regarding drug addiction cannot be determined by these differences in complex anatomical brain structures.

Second, the marijuana group reported use of multiple other substances, making it impossible to disentangle the effects of marijuana from those of other drugs. Without inclusion of a marijuana-only group or a group that reported use of multiple other drugs except marijuana, it seems premature to conclude that "...marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures..." Moreover, it is unclear whether these regional differences predate cannabis use or are a result of poly-drug use.

Given the above concerns, measuring regional brain differences offers no basis for speculation about arbitrary drug addiction behavior between cannabis users and controls. Structural brain differences between men and women exist, however this does not prove that they differ in ability based on gender. Without overt quantifiable behavioral measures and controlling for poly-drug use, these anatomical differences should not be attributed to marijuana use primarily.

References: DiDomenico R, Eaton RC (1988) Seven principles for command and the neural causation of behavior. Brain, Behavior and Evolution 31:125-140

Gilman GM, Kuster JK, Lee S, Lee MF, Kim BW, Makris N,Van der Kouwe A, Blood AJ, Breiter HC (2004) Cannabis Use Is Quantitatively Associated with Nucleus Accumbens and Amygdala Abnormalities in Young Adult Recreational Users. The Journal of Neuroscience 34(16):5529-5538

[Wild Bill]

IQ changes over one's lifetime. I'm not at all surprised a persons IQ might go down while going to high school in the USA. It's not easy on these young folks going to school everyday and being taught not to think.

 

Have they corrected for sampling error? Testing done on a wide cross section of the population or on inmates in juvenile correction facilities?

 

Abnormalities in the brain's grey matter, which is associated with intelligence, have been found in 16- to 19-year-olds who increased their marijuana use.

 

Were their brains tested for abnormalities before the increase in cannabis use? Perhaps the brain abnormalities caused them to self medicate. Which came first, the chicken or the egg?

 

They infer causality with nothing to back them up.

 

[t-pain]

Yes but I would guess that one of the parameters of the study was to rule out or in uses of other substances

 

you dont know about NIDA do ya?

[t-pain]

hey, heres the previous study, finally able to read it

http://jn.sfn.org/press/April-16-2014-Issue/zns01614005529.pdf

(cached http://web.archive.org/web/jn.sfn.org/press/April-16-2014-Issue/zns01614005529.pdf )

 

Cannabis Use is Quantitatively Associated with Nucleus
Accumbens and Amygdala Abnormalities in Young Adult
Recreational Users

 

 

Participants in this study were 20 young adult (age 18 –25
years) current marijuana users and 20 controls.

 

 

Marijuana participants were
not excluded if they had used other illegal drugs in the past; however, they
were excluded if they met abuse criteria for any drug other than mari-juana.

 

 

Alcohol Number alcoholic drinks/week 

CONTROL                 MARIJUANA GROUP

2.64 (2.38)                5.09 (4.69)

 

the marijuana group drinks DOUBLE the amount of the control group.

Cigarettes Number of occasional smokers
CONTROL                MARIJUANA GROUP

0                                    7
Number of daily smokers

0                                    1

 

the marijuana group has 8 tobacco smokers in it, the control has zeeeero.

 

 

still think these studies are accurate?

Edited August 11, 2014 by t-pain

[Wild Bill]

 

Alcohol Number alcoholic drinks/week 

CONTROL                 MARIJUANA GROUP

2.64 (2.38)                5.09 (4.69)

 

the marijuana group drinks DOUBLE the amount of the control group.

 

Cigarettes Number of occasional smokers

CONTROL                MARIJUANA GROUP

0                                    7

Number of daily smokers

0                                    1

 

Well then, it must be the marihuana. We all know alcohol and tobacco are the best things for developing minds.

[FranksHotPeppersAndMarijuana]

You can't call into question the results of a study just because according to you there is no way there can be a valid study done with teens. If the study has flaws, real flaws not imagined ones, then someone should point them out not just discredit a study based on past experience with studies. But until any real flaws are pointed out you are left with discrediting a study based on guessing. Reminds me an awful lot of what conservatives do with global warming studies.

[FranksHotPeppersAndMarijuana]

Tpain the methodology used in one study has nothing to do with another study. If one researcher used flawed methodology does that mean you throw out every single other study that examines the same issue? You aren't making sense you should be posting data about the study brought up by restorium2. Instead you are using data from other unrelated studies to discredit this one.

[FranksHotPeppersAndMarijuana]

I am not assuming it is valid. I am saying that you cannot assume it isn't. Guessing that a study is invalid because you assume that you can't do a proper study with teenagers or because other studies may be invalid is dumb. You can't contest a study with guesses. If you think it is invalid you look at the methodology and point out why it is, if it is. It's common sense.

[FranksHotPeppersAndMarijuana]

You can't say a study is invalid because you want it to be or because you wouldn't buy a used car from that woman.

[FranksHotPeppersAndMarijuana]

The University of Milwaukee conducted the study. They have no credibility?  If so why?

[FranksHotPeppersAndMarijuana]

From what I can see the author of the study also conducted a study on teen alcohol users versus alcohol+marijuana users.  If I am reading it correctly the outcome shows that the marijuana+alcohol users faired better than alcohol users alone, suggesting that marijuana possibly negates some of the deleterious effects of alcohol. Should be discredit that study too?

[FranksHotPeppersAndMarijuana]

I don't get this attitude of "I don't like you therefore your study is flawed." Or the attitude that "you funded the last study about marijuana and I think it was flawed therefore the other study you funded must be flawed too." No one will take anyone seriously that has that sort of prejudice towards a study without discrediting the methodology as opposed to discrediting the funder.

[Willy]

its still a bunch of misdirecting study, the nida folks do anything to make it appear cannabis  is the devil in plant life.. I wouldnt buy there study with anyones dime, let alone me own...

[Dr. Bob]

hey, heres the previous study, finally able to read it

http://jn.sfn.org/press/April-16-2014-Issue/zns01614005529.pdf

(cached http://web.archive.org/web/jn.sfn.org/press/April-16-2014-Issue/zns01614005529.pdf )

 

Cannabis Use is Quantitatively Associated with Nucleus

Accumbens and Amygdala Abnormalities in Young Adult

Recreational Users

 

 

Participants in this study were 20 young adult (age 18 –25

years) current marijuana users and 20 controls.

 

 

Marijuana participants were

not excluded if they had used other illegal drugs in the past; however, they

were excluded if they met abuse criteria for any drug other than mari-juana.

 

 

Alcohol Number alcoholic drinks/week 

CONTROL                 MARIJUANA GROUP

2.64 (2.38)                5.09 (4.69)

 

the marijuana group drinks DOUBLE the amount of the control group.

 

Cigarettes Number of occasional smokers

CONTROL                MARIJUANA GROUP

0                                    7

Number of daily smokers

0                                    1

 

the marijuana group has 8 tobacco smokers in it, the control has zeeeero.

 

 

still think these studies are accurate?

In my spare time I will look at this from a professional standpoint.  But if the figures on alcohol use are true, your point is valid.  If the study is well constructed, obvious bias or flawed logic can be used to reach incorrect conclusions.  A classic example is the 'marijuana causes brain damage' study the ignored the hypoxia and carbon monoxide in favor of claiming the 'brain damage' was caused by the marijuana.  In that study monkeys were fitted with low volume gas masks and the smoke from 2 ounces of marijuana was pumped in over 5 min.  Clearly carbon monoxide and or hypoxia from 'smoke inhalation' was the cause of any 'brain damage'- just as it is with the victims of house fires.  

 

Unfortunately, we have seen too many folks try to make the evidence fit their agenda driven conclusions.

[Restorium2]

From what I can see the author of the study also conducted a study on teen alcohol users versus alcohol+marijuana users.  If I am reading it correctly the outcome shows that the marijuana+alcohol users faired better than alcohol users alone, suggesting that marijuana possibly negates some of the deleterious effects of alcohol. Should be discredit that study too?

I like to compare study findings to life experiences. When they don't jive they don't jive. When they match up then you see it. Besides that, I still can't see how they could possibly have done a proper study given the subjects and how limited the science had to be, it was all hearsay. There was no actual marijuana involved, just accounts of stuff the kids thought might have been marijuana. Who knows what they were smoking? That's not science.

[FranksHotPeppersAndMarijuana]

In your life experience restorium2 when you smoked marijuana as a teen was it really marijuana or what you thought was marijuana? You're a gas!

 

Comparing studies to life experiences is like saying my grandpa smoked cigs for 60 years and 2 packs a day but didn't ever get lung cancer therefore cigs don't cause lung cancer.

 

And again the evil author of your study, in a separate study, suggests that marijuana may mitigate the deleterious effects of alcohol when used together. Why did she come to that conclusion when she is clearly in bed with NIDA who funds her studies?

[Restorium2]

In your life experience restorium2 when you smoked marijuana as a teen was it really marijuana or what you thought was marijuana? You're a gas!

Exactly. I lived the study and you obviously did not. You would probably be in the control group, as your lack of life experience in this is showing us. Edited August 11, 2014 by Restorium2

[FranksHotPeppersAndMarijuana]

You are shooting from the hip as always. You have no idea how the study was run because you didn't read it. You have no idea if they went on the teen's word alone or whether there was also testing. You are very good at googling things and parroting the second hand source but not so much when it comes to reading the primary source. That's what MY life experience with you has taught me.

 

But hey spread the word, cig smoking doesn't cause lung cancer and I know this because my grandpa didn't ever get lung cancer. How about we dispense with your life experience argument and focus on facts not just what you are guessing about.

[Restorium2]

You are shooting from the hip as always. You have no idea how the study was run because you didn't read it. You have no idea if they went on the teen's word alone or whether there was also testing. You are very good at googling things and parroting the second hand source but not so much when it comes to reading the primary source. That's what MY life experience with you has taught me.

 

But hey spread the word, cig smoking doesn't cause lung cancer and I know this because my grandpa didn't ever get lung cancer. How about we dispense with your life experience argument and focus on facts not just what you are guessing about.

There are so few teens that smoke marijuana and that's the only thing they do. Most try a lot of things. There was no way to do this study using the population of teenagers in America. So the study is flawed from it's inception. The person/group who thought it up was out of touch with reality. The people who performed it were pretending for that person/group. It was all orchestrated because it could not have existed in reality.

[FranksHotPeppersAndMarijuana]

I see. The knower of all has decided that the study couldn't possibly have been conducted because he knows it. There is just no possible way. Sounds a lot like the government contention that marijuana use and harder drug use go hand in hand or that marijuana is a gateway drug. Can't have done cocaine unless you first did marijuana right?  Wrong. Among the group I hung out with in my high school years drinking was not at all prevalent. Marijuana was the preferred "poison." That doesn't mean drinking wasn't prevalent in other places or even among other groups but suggesting that you know all and that there is no way this study could have been conducted is a bit arrogant.

 

Restorium2 has decided that there is no way a teen just smokes marijuana and that teens must also drink. You ARE really full of yourself aren't you?

[FranksHotPeppersAndMarijuana]

That's probably the best idea. Just label it junk science because you don't like the outcome. Just like the global warming outcomes and the republicans.

[t-pain]

frank, i didnt discredit this study, in fact i havent even read it. i would love to read the study and see if it is flawed.

 

i brought up the other study because it is similar! the age group (18-25), the number of subjects (40 in the april study, 97 in the new study), the methods (mri imaging of brains)... 

and because i wasnt able to read it in april when it was released, because i dont have access to medical journals.

 

i've reviewed a ton of these research studies. some are more based in reality than others.

Edited August 11, 2014 by t-pain

[FranksHotPeppersAndMarijuana]

Tpain fair enough.

 

All I am suggesting is that if empirical evidence is ignored then the (legalization) effort/cause looks dumb. If it accepted and you come up with a plan to avoid bad outcomes then the cause doesn't suffer the same black eye that the republicans suffer by just insisting that studies are wrong. Just saying a study is wrong because you don't think there is a possible way that they could've come up with teen marijuana users that don't use alcohol is dumb. And like I said the author of the study also authored another study that shows the harmful effects on the brain caused by alcohol may actually be mitigated by marijuana use. So is that also junk science zapatounidos?

Edited August 11, 2014 by FranksHotPeppersAndMarijuana