insomnia
"For many years, I had no problems falling asleep but after 4 hours would wake again, wide awake, mind racing, etc. I finally asked my doctor to prescribe Ambien and paid extra to get it. It was worth every penny. I found a whole tablet taken at bedtime still only let me sleep 4-5 hours. I had been told I might need to take another tablet if I woke too early, but didn't want to do that. So now, I don't take Ambien at night when I go to sleep. I take 1/2 of a 5 mg tablet when I wake up at 2 or 3 a.m. It works like a charm; I sleep another three or four hours. For me, 2.5 mg works just as well as 5 mg. Great sleep and I've never had sleep amnesia."