At least that's the determination of a study in Australia where over 3,800 men and women were involved. The study looked at these men and women who were born between 1981 and 1984 and followed them for the last 21 years.
In the study it was concluded that those who smoked marijuana or cannabis for at least six years or more were twice as likely to have delusions, hallucinations or psychotic episodes, than those who never smoked. The study conducted was on marijuana use and not frequency. The comparison was with those who had ever used and those who had never used.
According to a recent study by the United Nations, over 190 million people from around the world use cannabis. That equals to about 4% of the world's population.
This study has done nothing to stem the tide of debate from both sides of the issue. Recently an international group of drug policy experts published a book arguing that laws against cannabis have failed to curtail its use. But rather it led to huge numbers of arrests for drug possession in countries around the world. This has also caused social division and pointless government expense concerning marijuana and its use throughout the world.