One in six teenagers who regularly smoke the drug become dependent
It doubles risk of developing psychotic disorders, including schizophrenia
Heavy use in adolescence appears to impair intellectual development
Driving after smoking cannabis doubles risk of having a car crash
Study's author said: 'If cannabis is not addictive then neither is heroin'

Written By Ben Spencer

A definitive 20-year study into the effects of long-term cannabis use has demolished the argument that the drug is safe.

Cannabis is highly addictive, causes mental health problems and opens the door to hard drugs, the study found.

The paper by... http://www.dailymail.co.uk/health/article-2782906/The-terrible-truth-can...