insomnia
"Over 18 months, I had been taking non-extended release Ambien, starting out with five milligrams but quickly being switched up to ten.  Eventually, as stress and other factors were preying more heavily on my tired brain, the ten began not to work, so I was nibbling away at up to half of another 10 milligram tablet after not falling asleep, or not staying asleep.  Needless to say, that was not a good idea.  Finally, last week, I saw my doctor about it, and now I'm on Ambien CR and I'm managing to fall asleep and stay asleep--and knocking on wood."