Hi, I have had chronic insomnia for about 1 1/2 years, unable to catch any sleep unless I take a sleeping aid. My PD told me to stay away from Ambien because long term may cause dementia or increase your chances of a stroke. I am using a low dosage of Quentapine, which also may cause dementia if used long term according to a couple of studies. Unfortunatelly, I have no choice, either that or a long sleepless night and I feel awful the following night.