Marijuana use linked to schizophrenic-related brain changes

[edgarshade]

Medical News Today

Tuesday 17 December 2013 - 8am PST

With reader comments

The use of marijuana has been linked to the development of many health conditions. But now, researchers say heavy use of the drug could lead to poor memory and abnormal changes in brain function that resemble changes found in schizophrenic individuals. This is according to a study published in the journal Schizophrenia Bulletin. Marijuana is a mix of green and brown leaves, flowers, stems and seeds from the hemp plant Cannabis sativa. The leaves contain a mind-altering chemical called delta-9-tetrahydrocannabinol, more commonly known as THC. According to the National Institute on Drug Abuse, a part of the National Institutes of Health, marijuana is the most common illicit drug used in the US, with young adults having the highest prevalence of use.

Brain abnormalities found long after marijuana use stopped

Results of the study revealed that participants who began using marijuana regularly at the age of 16 or 17 demonstrated deterioration in the thalamus of the brain - an area important for learning, memory and communication. They also showed abnormal changes in the brain that are linked to working memory - an impairment that commonly leads to poor everyday functioning and academic performance. The investigators define working memory as the ability to remember and process information "in the moment," and transfer it to long-term memory if needed. These subjects also performed badly on memory tasks, and the same abnormal brain structures were apparent 2 years after they stopped using marijuana - indicating long-term effects from heavy use.

Marijuana use linked to schizophrenia

Furthermore, the investigators say the deterioration discovered in the thalamus resembles deterioration found in schizophrenic patients who used marijuana. Of the schizophrenic marijuana users, 90% had been using the drug heavily prior to developing the mental disorder. The researchers say these findings support previous research suggesting that regular use of the drug may contribute to changes in brain structure associated with having schizophrenia. Additionally, they note that if a person has a family history of schizophrenia, they could increase their risk of developing the disorder by using marijuana.

More...
http://www.medicalnewstoday.com/articles/270262.php

 

[LogicSoDeveloped]

Hmm...this is strange. It seems like I just read an article the other day from a good news source that said that cannabis use was not linked to schizophrenia.

 

[23536]

Hmm...this is strange. It seems like I just read an article the other day from a good news source that said that cannabis use was not linked to schizophrenia.

Probably this:

http://www.bluelight.ru/vb/threads/...k-between-teen-pot-use-and-schizophrenia-risk

Raw Story is not really a good news source (it publishes lots of blogspam), but it cited a Harvard study with a much larger sample size.

The Harvard study also gives a possible reason for the discrepancy:

Never mind that last bit.

 

[23536]

Abstract

Cannabis use is associated with working memory (WM) impairments; however, the relationship between cannabis use and WM neural circuitry is unclear. We examined whether a cannabis use disorder (CUD) was associated with differences in brain morphology between control subjects with and without a CUD and between schizophrenia subjects with and without a CUD, and whether these differences related to WM and CUD history. Subjects group-matched on demographics included 44 healthy controls, 10 subjects with a CUD history, 28 schizophrenia subjects with no history of substance use disorders, and 15 schizophrenia subjects with a CUD history. Large-deformation high-dimensional brain mapping with magnetic resonance imaging was used to obtain surface-based representations of the striatum, globus pallidus, and thalamus, compared across groups, and correlated with WM and CUD history. Surface maps were generated to visualize morphological differences. There were significant cannabis-related parametric decreases in WM across groups. Similar cannabis-related shape differences were observed in the striatum, globus pallidus, and thalamus in controls and schizophrenia subjects. Cannabis-related striatal and thalamic shape differences correlated with poorer WM and younger age of CUD onset in both groups. Schizophrenia subjects demonstrated cannabis-related neuroanatomical differences that were consistent and exaggerated compared with cannabis-related differences found in controls. The cross-sectional results suggest that both CUD groups were characterized by WM deficits and subcortical neuroanatomical differences. Future longitudinal studies could help determine whether cannabis use contributes to these observed shape differences or whether they are biomarkers of a vulnerability to the effects of cannabis that predate its misuse.

http://schizophreniabulletin.oxfordjournals.org/content/early/2013/12/10/schbul.sbt176.short?rss=1

 

[TheRapperGoneBad]

Furthermore, the investigators say the deterioration discovered in the thalamus resembles deterioration found in schizophrenic patients who used marijuana.

I'd imagine they'd always show the same signs if they were healthy or schizo because they are both using the same substance

Interesting post numbers, so is it saying they couldn't determine whether the differences in subjects were caused by marji or already existed?

Marijuana is a mix of green and brown leaves, flowers, stems and seeds from the hemp plant Cannabis sativa

Let me be the first to say Im not smoking leaves seeds or stems.

Marijuana use linked to schizophreniaFurthermore, the investigators say the deterioration discovered in the thalamus resembles deterioration found in schizophrenic patients who used marijuana. Of the schizophrenic marijuana users, 90% had been using the drug heavily prior to developing the mental disorder. The researchers say these findings support previous research suggesting that regular use of the drug may contribute to changes in brain structure associated with having schizophrenia. Additionally, they note that if a person has a family history of schizophrenia, they could increase their risk of developing the disorder by using marijuana.

Heavily using anything isn't good. Moderation is probably extremey important this case. And if your predisposed you should definitely tread with caution.
Honestly who expects to walk off scoff free after bombarding your brain daily with chemicals for years at a time if not for a life time.

 

[_DankOpiAmp_]

They always seem to match studies that discredit propaganda with slanted and misrepresented studies that support government lies.

They have graduated from completely fabricated studies, like those original cannabis and ecstasy studies that faked brain damage, to studies with small sample sizes that confuse cause and effect. Propaganda has gotten more subtle over time.

 

[TheRapperGoneBad]

The always seem to match studies that discredit propaganda with slanted and misrepresented studies that support government lies.

They have graduated from completely fabricated studies, like those original cannabis and ecstasy studies that faked brain damage, to studies with small sample sizes that confuse cause and effect. Propaganda has gotten more subtle over time.

Very interesting perspective doa.

Does make you wonder when this kinda thing pops up immediatly after an article claiming it doesn't cause schizophrenia.

 

[slimvictor]

Be careful interpreting the results of such studies.
What does it really mean?
The sample size is small, considering they are doing MRIs of brains, which means that they have to deal with lots of variance, and also that they are not always certain what certain brain morphology means (it "tends" to be associated with X)...

Future longitudinal studies could help determine whether cannabis use contributes to these observed shape differences or whether they are biomarkers of a vulnerability to the effects of cannabis that predate its misuse.

So, they don't know if the cannabis caused the differences in brain shape or not....

 

[cashfl0w_d0nkey]

I believe if the researchers set out to find negative effects of marijuana use, they will find them. There are definitely changes in the body that happen with regular marijuana use. To find the negativities and discuss then on their own paints an incomplete picture of marijuana use. Studies could be undertaken to measure creative output of control subjects vs marijuana users and you'd also find discrepancies. You could compare a number of other behaviors between marijuana users and non-marijuana users and find differences. I think people need to stop being so accepting of every new scientific study that comes out as bias is a real problem in most fields of science. I think logically it is apparent what are the differences between marijuana users and non-marijuana users. These scientists are slowly explaining that which is already apparent, a small piece at a time.

 

[treezy z]

at this point i've come to believe that marijuana may or may not lead some users to psychosis (in other words my views on it are like those of an agnostic towards spiritual matters), rather than brushing off all the evidence that it does as propaganda.