insomnia
"I have been using Ambien for several years and I seem to have built a tolerance so that I am no longer falling asleep nor staying asleep.  (Note:  I have used both Ambien and Ambien CR).  I was on a "local" trip and had forgotten my Ambien, so I asked my Dr if she had samples of anything that would help me sleep.  She gave me Silenor samples.  While I was extremely happy with the sleep, I did wake up "hungover" and had a hard time getting moving.  I also experienced very real hallucinations.  Don't know if they will lessen with use, but I am going to ask for a months supply to see if it works out after an adjustment period."