Professor Hall's findings are pretty much in line with earlier research on marijuana's effects.

People under 18 yoa shouldn't use it IMO, neither should pregnant women, much the same as alcohol or tobacco use is detrimental to developing bodies.

BUT, juvenile delinquency is not a new problem, and those already inclined to slack off, break the rules and so on will in all likely-hood develop several co-habits such as drinking to excess (a far worse problem), smoking tobacco, hitting up on harder drugs, promiscuity, or just plain aggressive behavior which is also habit forming if peer-encouraged.

Sub-adults need more time to develop emotionally to be able to handle the effects of ganja, which tends to suppress emotions.

The developing foetus can well do without it also.

As for Hall's assertions that ganja users are twice as likely to crash while driving than non-users of the herb,....well, that all depends......I don't think that that finding takes into account the number of drivers under the influence of alcohol, who are far more likely to crash than those on ganja.

The bit that really goes OTT is where Hall reckons that over-use of ganja brings on heart attacks,...a bit of a scare story there, ganja is more likely to de-stress a user, not build up hyper-tension leading to a fatal heart attack/stroke.

I think anybody would be struggling to find evidence of folks keeling over with heart failure over a joint!

As he says,"but people can die of heart problems that may have been brought on by repeated use.

The operative word being "may".

The story's just another wowser angle.