I have been taking antidepressants for some time. I tried recently to go off them, however the depression came back full force. When required (and they are not for everybody), they can be very beneficial to one's state of well being.
I am on two of them.
Citalopram (an SSRI), has not decreased my sex drive, it has made it very difficult to have an orgasm. For the first 3 months or so, it would take me at least 90 minutes of self pleasuring to achieve an orgsam, if it happened at all. Quite often my partner(s) would not be able to make me climax at all. At about the 6 month mark, things got a bit better. I could usually achieve an orgasm with a partner in about 45-60 minutes. The gradual increase of the drug is definately the worst part until your body gets used to all the effects.
Welbutrin (not an SSRI), which is piggybacked (in my case) with the Citalopram has entirely different properties. This drug has a side effect (in many people) which can increase one's sex drive. I have found that this drug alone does not make me come faster, just boosts the libido (so to speak). In some cases it has been used just for this property, to help people with a sexual dysfunction.
When I stopped taking the drugs (as I want to be drug free), a strange thing happened. The sensitivity in my penis increased by 1000%. I literally became a minute man, if I could last that long. Took about 2 months for things to get back to 'normal'.
Unfortunately, because I have not been able to control my depression without medication, I am finding myself on them again. Same sexual problems. Intense difficulty achieving orgasm, partners who are getting frustrated thinking that they are the cause etc. It is really a no win situation, though the Welbutrin cretainly does help a bit.