Xanax is used to treat anxiety disorders and anxiety caused by depression. Xanax is also used to treat panic disorders with or without a fear of places and situations that might cause panic, helplessness, or embarrassment. Xanax is extremely effective and offers quick relief from those panicky feelings. Xanax is used to treat anxiety disorders and anxiety caused by depression. Xanax is also used to treat panic disorders with or without a fear of places and situations that might cause panic, helplessness, or embarrassment.