The terrible truth about cannabis: Expert's devastating 20-year study finally demolishes claims that smoking pot is harmless

• 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' 

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 Professor Wayne Hall, a drugs advisor to the World Health Organisation, builds a compelling case against those who deny the devastation cannabis wreaks on the brain. Professor Hall found:

http://www.dailymail.co.uk/health/article-2782906/The-terrible-truth-cannabis-British-expert-s-devastating-20-year-study-finally-demolishes-claims-smoking-pot-harmless.html#ixzz53QLhYDLt