''Uppers and downers are in widespread use by military pilots today, and have been for a long time.'''
Yes, but that doesn't mean they're safe. I remeber using them during a period of extended operations. It became too much hassle going to the doc everytime you needed them, so we were given a large bottle for the ops officer to hand out. After a while I found one pill wasn't enough, so I started taking two. When two didn't work, I stopped taking them!
A friend of mine (not a pilot) got addicted to Stilnox in a very short time. She now cannot sleep at all without the drug and it's seriously affecting her health.