Cannabis use mimics cognitive weakness that can lead to schizophrenia

Researchers at the University of Bergen in Norway have found new support for their theory that cannabis use causes a temporary cognitive breakdown in non-psychotic individuals, leading to long-term psychosis. In an fMRI study published this week in Frontiers in Psychiatry, researchers found a different brain activity pattern in schizophrenia patients with previous cannabis use than in schizophrenic patients without prior cannabis use.

The results reinforce the researchers' model where cannabis users suffering from schizophrenia actually may have higher than non-cannabis using schizophrenics. This difference may indicate that the cannabis-user group did not have the same mental propensity for psychosis.

"While brain activity for both groups was similar, there are subtle differences between schizophrenia sufferers with a history of cannabis use and those who have never used cannabis. These differences lead us to believe that the cognitive weakness leading to schizophrenia is imitated by the effects of cannabis in otherwise non-psychotic people," explains Else-Marie Loeberg, lead author on the article and associate professor of Psychology at the University of Bergen, Norway.

The 26 patients involved in the study attempted difficult while in the fMRI machine. They were asked to listen to different syllables in each ear and try to say which syllable was spoken when instructed to concentrate on either the left or right ear—a difficult task for anyone but particularly difficult for who often have impaired attention, limited executive functioning and difficulty in processing verbal cues.

The study shows that schizophrenia sufferers with previous cannabis use had consistently higher levels of while undergoing these tests as well as a higher number of correct answers. These results are in line with previous conclusions from the Bergen researchers who support the idea that with schizophrenic characteristics do not appear to suffer from the same neuro-cognitive weaknesses as other patients with schizophrenia.

This implies that it is the cannabis use itself that leads otherwise non-psychotic individuals down the nightmarish path towards schizophrenia by imitating the cognitive weakness that is the main risk factor for developing the psychological condition.

More information: An fMRI study of neuronal activation in schizophrenia patients with and without previous cannabis use. Authors: Loeberg Else-Marie, Nygard Merethe, Helle Siri, Berle Jan ÿystein, Johnsen Erik, Kroken Rune, Jørgensen Hugo, Hugdahl Kenneth. Frontiers in Psychiatry, www.frontiersin.org/Journal/Ab… 389/fpsyt.2012.00094

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jway
4 / 5 (12) Nov 02, 2012
*If* cannabis caused psychosis, then the rate of psychosis in society would increase and decrease in sync with the rate of cannabis use. But it doesn't.

What is observed is that the rate of psychosis has remained unchanged over the years even though the rate of cannabis use has increased and decreased quite substantially. The researchers need to explain how cannabis could "cause" psychosis given the lack of an observable relationship between the two.

Additionally, ALL of the cannabis use observed in the study occurred DURING the cannabis prohibition when the stuff was supposed to be illegal to buy, possess and use. Given that illegal sales make cannabis much more accessible to minors than legal sales, it's not much of a compelling argument to keep it illegal is it?!!

Paranoid old men in the federal government keep cannabis illegal and make your children LESS safe!
PleonasticAxiom
3.9 / 5 (8) Nov 02, 2012
This is like saying when the price of ice cream goes up, the murder rates increase. Yeah sure that might be true, but your conclusions are frighteningly misleading. Don't blame the ice cream, blame the inflation. Don't push bias trash please.
Kerbox
2.1 / 5 (7) Nov 03, 2012
"This is like saying when the price of ice cream goes up, the murder rates increase."

Are you suggesting that by comparing the amount of cannabis use compared to psychosis rates it has the same relevance as ice cream use & murder? That might be the dumbest thing I have read all week. If cannabis was directly to blame, with no other variables, it would be only natural that psychosis rates should rise.

This has always clearly been bias science for political reasons, it is the only shred of negativity governments have been left with to justifying their stance on the issue.

The fact is it is poor science to try & link this directly to these conditions, especially schizophrenia, when clearly they are complex issues; development of schizophrenia has even recently been linked to infection in early childhood.

Cannabis likely helps the development of these problems but only with people who have genetic or psychological predisposition, current legislation also does nothing to help here.
Caliban
4.6 / 5 (9) Nov 03, 2012
*If* cannabis caused psychosis, then the rate of psychosis in society would increase and decrease in sync with the rate of cannabis use. But it doesn't.


That's it, jway.

This single observation --all by itself-- completely invalidates this "study" and shows it up for the agenda-driven excercise in confirmation bias that it is.

From the article:

The study shows that schizophrenia sufferers with previous cannabis use had consistently higher levels of brain activity while undergoing these tests as well as a higher number of correct answers. These results are in line with previous conclusions from the Bergen researchers who support the idea that cannabis users with schizophrenic characteristics do not appear to suffer from the same neuro-cognitive weaknesses as other patients with schizophrenia.


This sounds more like the cannabis use may in some way be mitigating or even repairing the underlying disease.
retrosurf
5 / 5 (3) Nov 03, 2012
The abstract:

"It is concluded that the present study show some differences in brain activation to a cognitively challenging task between previous cannabis and no-cannabis schizophrenia patients."

.. versus this article about the paper"

"This implies that it is the cannabis use itself that leads otherwise non-psychotic individuals down the nightmarish path towards schizophrenia by imitating the cognitive weakness that is the main risk factor for developing the psychological condition."

The two paragraphs seem unrelated.
A2G
2.7 / 5 (11) Nov 03, 2012
Why is it that all this effort is made to show how unsafe cannabis is and yet the real danger, big pharma drugs are "saving the world".

Pretty amazing what a lot of money can buy. My mom has had four major medical issues in her life. All four of them can be directly traced to "Big Pharma" drugs. Do you think my mom is the only one like this?

The four issues my mom had all could have been treated with cannabis it is now known with no real negative side effects.

In this case just follow the money. Legalize cannabis and get the government out of our private lives.
Anonym
2.9 / 5 (12) Nov 03, 2012
Reversing the obvious spin: The study's "cannabis users suffering from schizophrenia" are actually schizophrenics whose use of cannabis improves (compensates for) impaired cognitive function. In fact, other researchers have suggested the if there is a relationship between cannabis and schizophrenia, it is in sufferers' use of cannabis in just this way, to self-medicate.

MrVibrating
2.2 / 5 (9) Nov 03, 2012
The article concludes that cannabis use primes a subject with a schizophrenic predisposition, towards psychosis - however the simplest interpretation of the results is that, on the contrary, cannabis usage actually protects against such deterioration - even to the extent of improving their abilities!

Why the non-sequitur?

(Edit: oops, just as Anonym said before me)
tls67
4.3 / 5 (6) Nov 03, 2012
I have worked with consumers who suffer with mental illness, substance abuse and who are dually diagnosed for 20 years. In my experience, those who use substances do so in an effort to self medicate. Most people will report substance use/abuse before they will report symptoms of psychosis because of the stigma attached to such a horrible disease in this world. The agenda in this article is clear. It's actually quite amazing the study shows those who have used THC have more brain activity than those who haven't. This indicates the use of THC may be mitigating or slowing down the progression of the illness. Why not approach the study from that perspective? Oh! That's right! It's all about the money! Anti-psychotics have terrible & at times irreversible side effects but who cares b/c they are big money makers. Docs, remember your oath? Time to start following it.
Waaalt
2.3 / 5 (9) Nov 03, 2012
There is an increasing body of evidence that cannabis protects neurons, and promotes both new growth and adaptation.

The interpretation in the comments above that this study shows cannabis has a positive, protective effect on the minds of schizophrenics is completely consistent with that growing body of evidence.

And it is the simple explanation after all.

What the paper is proposing essentially is some other, separate sort of schizophrenia unique to cannabis users who got it from cannabis use and wouldn't otherwise have ever become schizophrenic. It's a laughably convoluted bunch of nonsense which ignores all the more widely available data.
elektron
1 / 5 (4) Nov 03, 2012
I don't know what those researchers have been smoking but I want some.
drloko
1 / 5 (1) Nov 04, 2012
I think many here are misunderstanding these results. The "higher brain activity" is not good under these circumstances. High levels of activity here lead to more difficulty concentrating.
Eikka
1.7 / 5 (3) Nov 05, 2012
*If* cannabis caused psychosis, then the rate of psychosis in society would increase and decrease in sync with the rate of cannabis use. But it doesn't.


More than likely, the incidence of psychosis has increased but it is not being reported because cannabis users are not likely to get diagnosed in the first place.

A psychosis doesn't necessarily make you pants-on-head crazy and psychotic individuals don't often even realize that they're having an episode, so a mild case can easily pass unnoticed. Even more so since cannabis users tend to isolate themselves to not get caught using the drug.

I know a few people who become "odd" when they're on the habit but who return to normal when they take a longer break from smoking weed.
MP3Car
5 / 5 (1) Nov 05, 2012
I think many here are misunderstanding these results. The "higher brain activity" is not good under these circumstances. High levels of activity here lead to more difficulty concentrating.


Are you a psychiatrist or neurologist? Otherwise, how do you infer that from the article when it mentions things like,

"The study shows that schizophrenia sufferers with previous cannabis use had consistently higher levels of brain activity while undergoing these tests as well as a higher number of correct answers. These results are in line with previous conclusions from the Bergen researchers who support the idea that cannabis users with schizophrenic characteristics ***do not appear to suffer from the same neuro-cognitive weaknesses as other patients with schizophrenia.***"

Notice the section in the asterisks... If higher activity was not beneficial, then how could "higher brain activity" cause someone NOT to suffer from the weakness the same as non-canabis users?
MP3Car
not rated yet Nov 05, 2012
I think many here are misunderstanding these results. The "higher brain activity" is not good under these circumstances. High levels of activity here lead to more difficulty concentrating.


Are you a psychiatrist or neurologist? Otherwise, how do you infer that from the article when it mentions things like,

"The study shows that schizophrenia sufferers with previous cannabis use had consistently higher levels of brain activity while undergoing these tests as well as a higher number of correct answers. These results are in line with previous conclusions from the Bergen researchers who support the idea that cannabis users with schizophrenic characteristics ***do not appear to suffer from the same neuro-cognitive weaknesses as other patients with schizophrenia.***"

Notice the section in the asterisks... If higher activity was not beneficial, then how could "higher brain activity" cause someone NOT to suffer from the weakness the same as non-canabis users?