Have drunk beer, and smoked weed for most of my adult life. Never thought it would be a good idea to try hard drugs, and rarely do spirits. Never had a problem really. Think issues arise for some, some not. Its very individual.
Not everybody smokes weed, and moves on to hard drugs, the same as...
Where is this mentioned?
I read the biggest fall was between these age groups, ie people giving up looking for work, and staying in education. Where did you read, that it was exclusively?