Cannabis is no soft drug, UN warns

New strains are as dangerous as heroin and cocaine

The study claimed a "significant" number of cannabis users experienced panic attacks, paranoia and "psychotic symptoms" during cannabis intoxication.

"Despite early claims to the contrary, cannabis dependence is a reality. Many people who use cannabis find it difficult to stop, even when it interferes with other aspects of their lives, and more than a million people from all over the world enter treatment for cannabis dependence each year," the report said.