depression
"I have had both depression and pain for the past 20 years.  After having some rather intensive back surgery 18 months ago, I decided to switch to Cymbalta instead of the Prozac that I'd been taking for many years to see if it would aid in the pain.  My initial result was hot sweats, but no other help.  I missed a day while I was on 60 mg and had vertigo and an electric twinging in my brain that actually made my vision jerk.  It went away about an hour after I took my Cymbalta.  This has since recurred every time I try to wean.  I cannot get down past 30 mg."