anxiety
"I had panic attacks and I've always had pretty high levels of anxiety, but since I got put on valium I have not had one attack or even felt like I was stressed.  I also stopped biting my fingernails down to the nub!  A happy side effect was that I was told by my doctor to take it if my back started to hurt (because of my scoliosis) and since I started doing that my back has not "gone out" like it did SO much before!"