I was thinking the same. And about the street drugs, i guess because it's not a constant thing, in my mind when i was getting high it was "just for today" or "one last time" and they made me feel good. While the paychiatric drugs aren't immediate and need to be used for long periods of time and can change you're personality without any enjoyment from it. I mean it all comes down to just the addictiveness of those street drugs that warp our minds. There's really no good reason to do them, we just convince ourselves otherwise.