What a complicated topic, I sure don't have the answers. I don't know the causes. For the kids I think it's more than peer pressure and boredom. We recently talked about how kids think they are bullet-proof or impervious to harm, that nothing will happen to them. Even if they see what drugs do to others they feel that won't happen to them. Kids tend to rebel, that's just part of being a kid. We as a society romanticize outlaws and standing up to authority. The more people in authority tell them not to use, the more some want to. They hear what bad things can happen to them if they use, yet they see adult and other kids using and functioning in society, often very popular kids in school as well as celebrities. Paul McCartney recently said some thing close to "When we were doing it, it all seemed so innocent". For the adults I don't know how much is gateway drugs, carryover from childhood, depression, anxiety, or what else. Getting hooked on prescription painkillers is a factor but I don't know how big in the overall scheme of things. Everything is an epidemic on the national news, they tend to sensationalize everything. That's probably a lot like how those teenagers feel about us when we warn them of the dangers of drug use.
Once you are addicted, you are addicted. Some people can stop smoking tobacco, coffee, or excess alcohol cold turkey, some just can't. With many of these drugs we are talking about, the body really craves them and your have great physical pain and discomfort if you stop. Some of that is mental but some is physical. For some people once they get hooked it is a lot like a disease. They can't function without it. And their body craves it, sometimes for a long time.
I don't know why use seems to track the economy. Is it because in bad times people are more despondent and become users or because selling is a way to make money when nothing else seems to work so ease of access goes up and you might have more price competition. Probably a combination. I don't think the growers, makers, smugglers, or dealers are the whole problem. As long as somebody is willing to pay for it, someone will supply it. I certainly don't give the smugglers and dealers a free pass, but I think the ultimate solution to them is to take the profit out of the trade. Whether that is by attacking the users part of the equation or making he drugs available to the addicts so they don't have to buy from a dealer, I don't know. Some European countries are experimenting with that. it may take more than one or two generations to see what the overall effect is, but maybe we can learn from them.
Why do I feel so hopeless when I think about this topic? I just don't see a solution and I hate to see the lives ruined.