Ativan can be used as a PRN. It's a bit longer-acting than Xanax. Some people also take Ativan before sleep. Generally, although all of the benzos can be addictive, longer-acting will translate to less addictive. And there are alternatives to the benzos for anxiety, like BuSpar. The alternatives tend to work better for people who have not taken benzos, because they are more steady, long-lasting treatment - you won't feel an immediate effect with them. Some people who are used to benzos will find that a bit of a let down and might think it isn't working.