I take gabapentin for anxiety and to sleep. I take a big dose, 1200 mg all at once and it helps a lot. I take 200 mg PRN and that's less helpful but it does help me calm down before bed a little and 2 doses usually puts me to sleep if I'm having a little trouble (it doesn't on bad nights, then I take some extra klonopin very reluctantly). I never could take it in divided doses like most people do because it knocked me out (except when I was IP and manic, then I was watching the clock for my next dose time).