How Quickly Can You Get Dependent On Xanax? I Have

How quickly can you get dependent on Xanax? I have taken .5 mg of Xanax twice most nights for about a week now. One night in that week I didn't take any and last night I only took .5 once and .25 once, so I cut the dose somewhat. I don't want to develop a dependence on this, but I'm having sleep issues and it helps me relax and sleep.