My understanding (I could be wrong) is that ativan can be addictive. I take ativan 3x daily for ongoing stress & know that I will have to titrate off it when the time comes.
It's fairly short acting (for me); it helps me fall asleep - doesn't keep me there.
kt & husband use seroquel for sleep; kt has been on trazadone in the past for sleep as well.
Good luck to your difficult child in getting a good night's sleep. It can be a challenge!