hi I take ambien CR 12.5 mg as needed, and have for about the last two months. recently is worked fine, but in the past if I've taken a nap that day or drank a little caffeine I think it didn't work as well. But more recently on the days it's worked, I can remember waking up after about 8 hours but not 'jumping out of bed' um more somber? Like I went to get a haircut one morning and just remember feelings kind of like depressed mood. um maybe not all because of the ambien!