One more and I'll shut up awhile.
I think the true cause of much of the youthful desire for chemical escape (and alcohol is still by far #1!!!!) has to do with the ever-increasing pressure to excel competitively. I could see this coming back in the 80s when Japan was so much in the media, and how much people there compete. It is a natural outgrowth of an increasingly crowded country, the same way a hundred cows will be mellow on 300 acres but be pushing and shoving each other if you put them on 20.
I'm getting old now, but when we wanted to play baseball we just got together a group of neighborhood kids, went to a vacant lot and played, or did it in the back yard. Now? OH NO! That won't do! You have to have uniforms and drive the kids 10 miles to an official ballpark and have umpires and a whole organized system of intense competition where the parents get in the faces of the officials and scream or even actually hit them. Meanwhile, suburban neighborhoods look like ghost towns. Nobody is home there, or if they are they dare not come outside and interact like parents used to do in my neighborhood. That creates a breakdown in parental communication and authority.
Same in school. When I was in kindergarten, tying your shoes and counting to 100, knowing your ABC's - those were the standards. Now, kids are expected to start learning a second language and do math and spell out words, etc.
There's little time to be a kid anymore, and almost every activity we did just for fun has been perverted into some kind of survival of the fittest. We're piling more and more competitive pressure on them at earlier ages. It's easy to see why kids try to get away from that, even if for only a little while.
Then at the same time that there is little time to be a kid anymore, adult decisions are put off longer and longer. People who are 34 are just now getting a job.
I'm glad I grew up when I did.