[Kizzy]

http://www.bmj.com/content/325/7374/1212

Although most young people use cannabis in adolescence without harm, a vulnerable minority experience harmful outcomes. A tenth of the cannabis users by age 15 in our sample (3/29) developed schizophreniform disorder by age 26 compared with 3% of the remaining cohort (22/730). Our findings suggest that cannabis use among psychologically vulnerable adolescents should be strongly discouraged by parents, teachers, and health practitioners. Policy makers and law makers should concentrate on delaying onset of cannabis use

1 in 10... who likes those odds?

This is the British Medical Journals opinion...not mine.