depression
"I had a terrible reaction to Cymbalta called Neuroleptic Malignant Syndrome.  Stiff muscles, couldn't stand let alone walk to the phone, couldn't feel my hands and feet, fever, blood pressure through the roof. After a family member found me on the floor drooling I was taken to the hospital in an ambulance.  I realize this is a rare side effect, but it does happen.  What's great for one person may not be great for the next."