Fluoxetine
"I went on a course of 20mg per day for about 2 years, basically on advice from duty nurse. This was after telling her of mild anxiety, low energy and low moods. After about 4/6 weeks my general mood/positive feeling and energy levels were enhanced. After approximataly 2 years the effects wore off totally.  It is now 15 months since I stopped, I am now about to restart, hopefully to get those positive moods back."