insomnia
"Its very strange at first, serious nightmares, its almost like lucid dreaming, very 3D, and you have more ability to make decisions in the dream.  It takes me at least 2 hrs for it to work, and I have taken it and stayed in bed for hours with a horrible nights sleep.  It works different than ambien, it gives me a sedative feel.  Make sure you have at least 7 hrs to sleep.  Once you get used to it, the negative side effects I think go down.  The half life is longer than Ambien and that's good but it still does not have the effect of a quick acting sleep med.  More expensive too because its new and there is no generic yet."