A team of researchers from King's College London and Sapienza University Rome found that smoking high-strength "skunk weed" cannabis can cause critical damage to the vital nerve fibers in the brain called corpus callosum. This part of the brain handles the transmittance of neurons from the right to the left hemisphere of the brain, and vice versa, scientists said.
Previous studies revealed that the long-term use of cannabis can increase the risks for psychosis, and that the alterations in a person's brain structure and function may cause this mental disorder.
In the new study featured in the journal Psychological Medicine, the team of experts examined the effects of cannabis potency on the structure of the brain. The research is known to be the first to suggest that the greater use of skunk weed may damage the corpus callosum.
Neurobiologist Dr. Paola Dazzan explained the harmful effects seem to be connected to the level of tetrahydrocannabinol (THC) in cannabis. Typical kinds of cannabis contain about 2 to 4 percent THC, but the more potent drugs contain 10 to 14 percent THC, experts said.
Dazzan said that when they looked at the corpus callosum of those who smoke high-strength cannabis, they found that there was a significant difference in the white matter compared to people who have never tried the drug, and people who smoke low-strength cannabis. The THC chemical acts on cannabinoid receptors which the corpus callosum contains.
The team utilized two scanning methods to examine the corpus callosum in the brains of 56 patients who reportedly experienced a first episode of psychosis, and 43 healthy participants from the local community. One method required the use of diffusion tensor imaging (DTI) while the other method used magnetic resonance imaging (MRI), researchers said.
The scans discovered that people who used high-potency cannabis daily had a higher mean diffusivity--a marker of damage in the white matter--in their corpus callosum. Dazzan said it indicates a problem in the white matter of the brain and makes the corpus callosum less efficient.
"We don't know exactly what it means for the person, but it suggests there is less efficient transfer of information," said Dazzan.
Meanwhile, Dazzan urged the public to change how they perceive the use of cannabis.
"There is an urgent need to educate health professionals, the public and policymakers about the risks involved with cannabis use," added Dazzan.
Photo : Allan Ajifo | Flickr