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.
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Mother deer rushed towards the infant distress calls of seals, humans and even bats, suggesting that these mammals share similar emotions
In the forests of eastern Australia, a squadron of social spiders faces off against an army of the world's most dangerous ants in a pitched battle for survival
Contrary to some earlier projections, the world's population will soar through the end of the 21st century thanks largely to sub-Saharan Africa's higher-than-expected birth rates, United Nations and other population experts said on Thursday.
Archaeologists got to the root of an ancient hairstyle when they unearthed a 3,300-year-old body with 70 hair extensions
A major international study finds that killings among chimpanzees result from normal competition, not human interference.
Clownfish travel hundreds of kilometres, but it is the larvae rather than the adults that migrate
U.S. government researchers working with divers and sonar equipment have located the wrecks of what they dubbed "forgotten ghost ships" in waters just outside San Francisco's Golden Gate strait.
"It's spooky," a Clearwater, Fla., fisherman said, comparing the toxic algae bloom to "boiled red Georgia clay"
Physicist Danielle Bassett has been awarded a MacArthur Fellowship based on her work studying the human brain. She talks with Melissa Block about the advances it may lead to.
A team of researchers are using multispectral imaging to uncover hidden text on a 1491 Martellus map, one of the most important maps in history. Lead researcher Chet Van Duzer thinks the discoveries will allow historians and scholars to see just how the map influenced cartography in its time.