I was using trazodone and zoloft early in college in order to deal with depression.
I was told by the doc that I shouldn't take it for very long because of a number of negative sides (although who doesn't want priapism?).
Eventually I stopped using it - but I didn't know that you shouldn't stop cold turkey. I had horrible stomach and gastrointestinal issues for about a month. I also slept for 3 days straight through at one point when first off of it - it had screwed up my system.
I later was told by a doc that in some people using that drug, they don't develop a tolerance and need more, but instead become more sensative to it and the same amount gives them increased sides over time.
All in all, like what everyone else is saying, I'd avoid it.