Oh my word, I was put on Lexapro, or escitalopram on the first day it was available for RX in the States in 2002, that stuff is like a second generation antidepressant and it will annihilate that aspect of your life, if you are a male. I can remember seeing my treating psychiatrist at the time, throwing that stuff in the garbage can and telling them stopping that in your life sure as heck was not a way to battle depression. It was however a sure fire way to cause it. He thought that was funny and it made me even madder. Look I am an MD and there is a condition called HSDD, (Hypoactive Sexual Desire Disorder) that affects around 10-12% of females, and there are medications for it. Look I was practicing rural doctor and I have had husbands and boyfriends tell me they were going to destroy the whole state, to please do something. If this was a sudden change chances are there is a reason and it would be a medical one. How about take her out to a nice dinner with a complementary follow up to your medical professional. That sort of thing is extremely frustrating sorry it is happening.