Yeah man, anti-depressant pills are no good for short term stuff IMO. My mom wouldn't except that I was bi-polar and would claim my depression was just passing, but when I had my first noticable manic episode and was put into a psychiatric hospital she knew I actually needed those types of pills. I stopped taking them after a while and quit them all cold turkey and never had anything really bad happen. But my friend was on zoloft for a few years and quit by lowering the dose him self every two days until just stopping. He had no bad side-effects. But sounds like your sister? should just go back on the pills, and slowly take herself off them.