That's not true. A lot of people's stress is internal. And what's the difference anyways? The human condition is to suffer, get old, and die. Sounds to me like drugs are probably the most rational and logical thing you can do, besides suicide. I'm being a little bit of a downer, I know, but the reality of life is pretty terrible. Fortunately, me and most others can just ignore what life is about (most of the time) and carry on like anything we do makes a difference.
Moreover, if politicians wanted to act upon it, they would just legalize all drugs and call it a day.
Happy to hear that there's an ever growing base of data to support this, but sadly acting upon that data is not exactly top priority for politicians :/