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.
With funding from the Defense Department, scientists have begun work on devices that would use electric pulses to realign a memory process gone awry
On Friday, the Food and Drug Administration released a vital set of numbers about the routine use of antibiotics …
Side order of veg with that mammoth leg? The Neanderthal diet was probably more varied than we think – using vegetables, herbs and different cooking techniques
An exoskeleton that enables movement and provides tactile feedback has helped eight paralysed people regain sensation and move previously paralysed muscles
A female western gray whale set a new record swimming from Russia to Mexico and back, a total of 13,988 miles, in 172 days
Scientists operating a remote-controlled vehicle about 2,000 feet below water get a rare glimpse of a sperm whale. CBSN's Vladimir Duthiers and Elaine Quijano report on the video.
According to the experts, "blinking is like a kitty kiss"
Genetic profiling of cancer cells can help guide treatment, but such profiles can be ambiguous. Results would be more accurate if all labs tested normal cells from each patient, too.
Researchers in Kenya uncover tools dated to 3.3 million years ago, long before the first humans, as we know them, walked the Earth.
Researchers are facing up to methodological flaws that plague functional magnetic resonance imaging, but the interpretative problems might be harder to solve