depression
"When I first started Effexor XR, it seemed to really help for a while.  After a while we had to increase the dosage to its maximum, and had to add the max 80 mg of Prozac to keep me "normal".  After about a year, I started having real problems with exhaustion and fatigue.  It took a lot of testing and doctors and finally two separate sleep studies to find that my deep sleep had been disrupted significantly -- essentially I was getting NO restorative sleep, even when I slept for 8-12 hours!"