depression
"Began taking xanax during a time when my one and only child left home for college and I lost my job a month later.  It allowed me to cope and move forward.  The most I ever took was 1 mg per day, but I now take .25 when I have periodic depression and anxiety.  I sometimes go 6 weeks without taking one.  The best way to describe it is like rebooting your mind.  Life saver for me."