A new study by researchers at Kings College London found that people who smoked high-potency pot had significant damage to the white brain matter inside their corpus callosum, UPI reports.
The study also showed that people who smoked super strong weed known as 'skunk' showed even more significant white matter loss.
Corpus callosum is a neural pathway connecting the left and right halves of the brain.
The findings were published this week in the journal Psychological Medicine.
For the study, the researchers performed MRI scans on the brains of 56 patients who had paid a visit to a London hospital with complaints of a first episode of psychosis. The researchers also scanned the brains of 43 healthy participants.
"We found that frequent use of high-potency cannabis significantly affects the structure of white matter fibres in the brain, whether you have psychosis or not," Paola Dazzan, a neurobiologist at Kings College, said in a press release.
"This reflects a sliding scale where the more cannabis you smoke and the higher the potency, the worse the damage will be."
The main psychoactive ingredient in weed, tetrahydrocannabinol (THC), is present up to 14 percent in concentration in modern skunk strains.
"As we have suggested previously, when assessing cannabis use it is extremely important to gather information on how often and what type of cannabis is being used," Dazzan said.
"These details can help quantify the risk of mental health problems and increase awareness on the type of damage these substances can do to the brain."
However, the study cannot confirm the link between high levels of THC in cannabis and changes to white matter. As Dazzan noted,
"It is possible that these people already have a different brain and they are more likely to use cannabis. But what we can say is if it's high potency, and if you smoke frequently, your brain is different from the brain of someone who smokes normal cannabis, and from someone who doesn't smoke cannabis at all," she said, according to the guardian.
According to ScienceDaily, Dr Tiago Reis Marques, a senior research fellow from the IoPPN at King's College London, said:
'This white matter damage was significantly greater among heavy users of high potency cannabis than in occasional or low potency users, and was also independent of the presence of a psychotic disorder.'
