Hell, just look at all the drug prevention programs aimed at youth and how that's worked out. It doesn't work, because once you tap the pleasure center of the brain, a lot of people will want more of whatever did the tapping. Add to that youths' natural defiance of authority, and any preventative measures against drugs, corruption, or teenage pregnancy for that matter are doomed to fail.
When you are prescribed Adderall and someone comes and tells you that this is bad, it's hard to believe them, you know
Well, the reason why drug prevention programs fail is that they don't tell you the truth. In school, once in a while we had a lecture about that and you know what, all they tell you is that drug usage causes death, it kills people and that's why it is bad. Rarely but sometimes they would add that drug usage cause depression but this part was mostly ignored but death was strongly highlighted. Youth don't care about it, you have to tell them truth: Drugs don't kill that easily, especially if they are pharma grade. What they do is that they mess with your psychology, destroy your brain's reward center and you don't feel a joy in life anymore, you have zero motivation, zero reason in your head to live or do something. They don't explain these details, they never talk about dopamine and serotonin, this is the real problem.
I would say prescribed and otherwise are different. When someone smokes weed, that is not killing them right away neither, it is a slow process that may happen when they are elderly, but nothing happens at that moment, unless they smoke and drive. However, when they are prescribed it, that means they need it.
In many nations of the world weed is prescribed as medicine for people who are doing chemo, you know why? Because during chemo you can't eat and you are constantly in pain, as someone who had a loved one go through chemo for 6 months, I can tell you that weed would have been great if it was legal where I live. Why? Because since it has a numbing effect, and makes you hungry, that person would have gone through the same process better, eat better, less pain. So what is right may change depending on the situation.