"Skunk weed" cannabis were discovered to cause major damage to very important nerve fibers that links the left and right brain hemispheres.

The weed damages the nerve that allows the brain's left hemisphere to communicate with right hemispheres, which is called corpus callosum.

About 500 cannabis cafes were located inside Netherlands wherein people are allowed to buy almost five grams of marijuana for their personal use.

"Skunk weed" which is popularly known as a kind of cannabis are also the most widely used and it contains high level s of tetrahydrocannabinol (THC).

Consumption of the drug causes more harm, based on some evidence. But it was not clear if the plant really have connection with psychosis.

"We found that frequent use of high potency cannabis significantly affects the structure of white matter fibers in the brain, whether you have psychosis or not," said by the  Lead researcher Dr Paola Dazzan, from the Institute of Psychiatry, Psychology and Neuroscience at King's College London.

"This reflects a sliding scale where the more cannabis you smoke and the higher the potency, the worse the damage will be."

Those 56 patients who reportedly have first episode of psychosis including 43 healthy volunteers were scanned by two scanning techniques in order to examine "white matter" in their brains.

The white matter is the part of the brain where the nerve signals travel, it is made up of "axons" or neural fibers.

The white matter is prone to damage when high-potency cannabis was frequently used, based on the study published in the journal Psychological Medicine.

Co-author Dr Tiago Reis Marques, also from King's College, 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."

Dr Dazzan added: "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. 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."