anxiety and stress
"Prozac worked great for me for about 2 years and then it quit being effective. Apparently this experience is so common it's even called "Prozac poop-out." At age 41 I started taking 10 mg daily, then increased to 20. For the first week or two I felt slightly nauseated and had trouble getting an erection. Then those side-effects vanished, and I felt not only happier but more functional (at the time I was a university professor). I wrote 2 published novels during those two years. A wonderful side-effect is that I gained total ejaculatory control. Suddenly I was the lover I'd always wanted to be! But after the Prozac honeymoon, I found myself feeling anxious and depressed again and the Prozac was just making me sleepy. So I quit. C'est la vie."