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 cognitive abilities 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 cognitive tasks 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 schizophrenia patients 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 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 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/Abstract.aspx?s=996&name=schizophrenia&ART_DOI=10.3389/fpsyt.2012.00094
Jul 26, 2007
jway
4.3 / 5 (11) Nov 02, 2012What 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, 2012Kerbox
2.3 / 5 (6) Nov 03, 2012Are 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, 2012That'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:
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"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
3.7 / 5 (7) Nov 03, 2012Pretty 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
3.9 / 5 (8) Nov 03, 2012MrVibrating
3.2 / 5 (5) Nov 03, 2012Why the non-sequitur?
(Edit: oops, just as Anonym said before me)
tls67
4.3 / 5 (6) Nov 03, 2012Waaalt
3 / 5 (6) Nov 03, 2012The 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 (1) Nov 03, 2012drloko
1 / 5 (1) Nov 04, 2012Eikka
3 / 5 (1) Nov 05, 2012More 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, 2012Are 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, 2012Are 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?