I can only say I too was prescribed traz for a trial thing from my pdoc (along with my mood stabilizer) to see if it would help me with the bipolar sleep issue, I tried it and got a terrible headache, almost migraine status, so I stopped it, doc said it was okay, and gave me Ativan instead for when I have those nights. Ambien, the sleeping pill was short lived, and gave me killer headache and constipation the day after.
If I am not mistaking Trazadone is also known as Desyrel??
My advice is if it doesn't do much for you, do not hesitate to call your pdoc, he or she may give you an alternative, it is not good for us "bipolars" to lose sleep, cause we do burnout, and that can be a nightmare.
I wish you lots of luck with this, and please know you can hang out here anytime, there are a lot of terrific people here to talk to

Take care,
DE