I've only been on Viibryd for 4 days but have had 3 nights of very bad sleep. Not being able to sleep is a deal breaker for me. I have mild circumstantial depression and had sleep problems to begin with, but could sleep quite well with a Unisom every night. I see many, but not all folks have sleep issues while on Viibryd. Does this side effect go away after a while? I tend to be the irritable depressive type person and I don't care about the sexual side effects. But I need to sleep. Any ideas?