Casual marijuana use may damage your brain

[Bill the Cat]

http://thechart.blogs.cnn.com/2014/0...ge-your-brain/

The study, published in the Journal of Neuroscience, is the first to link casual marijuana use to major changes in the brain. And according to the researchers, the degree of abnormalities is based on the number of joints you smoke in a week.

Using different types of neuroimaging, researchers examined the brains of 40 young adults between the ages of 18 and 25 who were enrolled in Boston-area colleges. Twenty of them smoked marijuana at least once a week. The other 20 did not use pot at all.

The marijuana smokers were asked to track their cannabis use for 90 days. All were given high-resolution MRIs, and users and non-users' results were compared.

Researchers examined regions of the brain involved in emotional processing, motivation and reward, called the nucleus accumbens and the amygdala. They analyzed volume, shape and density of grey matter - where most cells in brain tissue are located.

"I think the findings that there are observable differences in brain structure with marijuana even in these young adult recreational users indicate that there are significant effects of marijuana on the brain," says Dr. Jodi Gilman, lead author and a researcher in the Massachusetts General Center for Addiction Medicine. "Those differences were exposure-dependent, meaning those who used more marijuana had greater abnormalities."


http://jn.sfn.org/press/April-16-201...1614005529.pdf

[rogue06]

Not surprising that it would have negative effects on those who's brains have not yet finished forming (IIRC that takes place at 25).

[Jedidiah]

I am not sure my brain is finished forming at 72.

[Paprika]

Abnormalities aren't necessarily negative.

[Cow Poke]

Not surprising that it would have negative effects on those who's brains have not yet finished forming (IIRC that takes place at 25).

Didn't you start at 12?

[Cow Poke]

Abnormalities aren't necessarily negative.

Just mostly usually always.

[Sparko]

I guess that explains Mickiel.

[Paprika]

Just mostly usually always.

In this context, abnormalities means differences in certain parts of the brains when comparing marijuana users to non-users. There is nothing in the study that indicates whether such differences are bad.

[Catholicity]

Well common sense says that the Inhalation of Smoke cuts off the oxygen supply to the body which cuts off the oxygen supply to the brain. We know that the Inhalation of Carbon Monoxide and Carbon Dioxide Suffocates not just Lung Tissue but will kill Brain cells. The reason for these abnormalities isn't that hard to figure out. Reduce the oxygen turn up the poison gas= brain lung problems.....

[Teallaura]

Abnormalities aren't necessarily negative.

They found evidence of growth in adult brains. Growth in the adult brain normally only occurs after the brain has been damaged - in other words, the brains were repairing themselves after 'casual' exposure which is a good indicator that damage had occurred.

[Paprika]

They found evidence of growth in adult brains. Growth in the adult brain normally only occurs after the brain has been damaged

Wrong. Firstly, the study was cross-sectional: it is not known if the growth was prior to or after marijuana consumption. Secondly, adult brains can and do experience growth in grey matter, even rapid growth.

[Teallaura]

Wrong. Firstly, the study was cross-sectional: it is not known if the growth was prior to or after marijuana consumption. Secondly, adult brains can and do experience growth in grey matter, even rapid growth.

The marijuana group had it; the non-using group didn't.

[Paprika]

The marijuana group had it; the non-using group didn't.

You know what they say about correlation and causation? That the marijuana group has the brains growth doesn't necessarily mean that the growth occurred after marijuana consumption. This observation isn't merely mine, the authors of the study noted that

This preliminary study has several caveats. First, the sample size does not provide power to examine complex interactions such as sex differences. Because this is a cross-sectional study, causation cannot be determined, although marijuana exposure parametrically correlated with structural differences, which suggest the possibility of causation. Longitudinal studies are needed to determine whether marijuana exposure explicitly leads to the differences observed in this study.

(emphases mine)

[Teallaura]

Granted - so what? It clearly seems to be related to the marijuana use and the 'we don't know when' thing is meaningless since the control didn't have the same condition. Never said it established causality - but it does establish a strong indicator of relationship.

[Cow Poke]

In this context, abnormalities means differences in certain parts of the brains when comparing marijuana users to non-users. There is nothing in the study that indicates whether such differences are bad.

You'll please forgive me if I'm dubious of the likelihood that the abnormalities would be beneficial when they start with the act of taking some dead leaves, wrapping them in tissue paper, setting them on fire, sticking it your mouth and purposely sucking the noxious gases into your lungs.