I used Citalopram for 6 months, I felt amazing on it, always positive and always psyched up, full of energy, very social and not really bothered by anything and just feeling at my optimum all the time.
However, when I voluntarily stopped it took me over a year for my sex drive and erections to recover, though I never had any problems at all while on it and it had actually increased my sex drive.
I'm glad I stopped using anti-depressants because I think long-term use would permanently alter my brain and perhaps make me dependent on the same or similar medication for the rest of my life...
BUT, I do believe it's purpose is to help a person get through a rough patch, to give them a boost when they need it, but not to rely on it forever.