depression
"I've been on 75/mg of sertraline (generic version of Zoloft) for 5 years.  It has helped a great deal with my depression, anxiety, and compulsive negative thoughts.  I've gotten off of it twice; I find that I don't have withdrawal symptoms if I go off it gradually.  The side effects I've had are a decrease in sex drive (which comes back once I stop taking it) and a general feeling of apathy.  It doesn't make me happy, it just makes me not so sad and much less obsessive.  I do, however, feel I have lost a lot of creativity and motivation.  Other than the apathy and lack of a sex drive, it works extremely well at stopping the depression and anxiety."