You are right in your concerns. Sounds like your friend has developed a pretty large tolerance to them, and yes, they disrupt sleep stages and will in time, worsen any pre-existing insomnia. Although some people can withdraw fairly easily, the majority will go through a lengthy withdrawal that can last a year or two with some lingering symptoms after that. Looking under benzo withdrawal will give some webpages of information. A Professer Ashton who discovered the protracted benzodiazepine withdrawal syndrome is referred to alot on some of these websites. There are really no other meds that will get rid of the withdrawal without causing more problems..the actual cure is simply letting the brain have as much time as it needs to straighten out the chemical imbalances the drugs cause. That time does vary from person to person, drug to drug. Have her take a look and see what she is getting herself into. Most people like her end up in the hospital or on a bunch of psych drugs if she allows this to continue.