My day job involves working with 16-25 yr olds some smoke pot or do other drugs, some drink to excess and some are just young adults trying to make their way in the world. The pot smokers, (and those who do Amphetamines) have a tendancy to have more problems with life than the others, as these two drugs seem to distroy ambition, and enthusiasm, and can tip a fragile mind over the edge. Also long term use means they are mixing with criminals who have a vested intrest in keeping them on the stuff, and moving them onto harder drugs. Last month I visited three different YP in various Mental Hospitals. This is not dogma, just 18 years experience.