There are a lot of other variables though, too... Adderall is a medication after all, and does provide benefits.
One of these benefits is that I don't drive as fast. I'm not sure I understand why, but when I'm on ADD meds I tend to catch myself driving 5 mph under the speed limit... Before I was on ADD meds and when I'm not taking ADD meds, I tend to catch myself driving 15 or 20 mph
over the speed limit. So which would kill me faster, taking a reasonable amount of a prescribed stimulant medication, or getting into a car accident at 80 mph?
Another benefit can be weight loss for some. Granted, I'm not overweight and wouldn't be without ADD meds, but being closer to one's ideal weight (as long as they're not under it) is surely healthier than being overweight.
Another benefit is being able to function better both at work and in life in general. If one's quality of living is higher, they're happier and will make better decisions and whatnot, as opposed to being constantly stressed out just trying to keep their life together and stay on top of their work and other responsibilities. That's gotta be better for one's health as well.
If you consider all of the other forms of self-medication people engage in, such as gambling, reckless driving, smoking, irresponsible sexual behavior, picking fights, substance abuse, etc. I think it's safe to say that medicating ADD is generally a good thing.
The ephedra did essentially the same thing for me that adderall does, btw, though it's not as safe as taking adderall properly.