depression
"I have suffered from depression for over 30 years now and have gone on and off of Prozak several times during the years. 

What I have found is that when I'm taking it I will feel so good that I always eventually stop taking it thinking that I do not need it but then after a few months I need To go  back on the medication and within no more than 2 weeks I feel like a new person.

While writing this I only hope that I never foolish enough to stop taking Prozak."