Avoid taking Ambien (or similar drugs) for a prolong period, it is known to significantly increase the risk of dementia.Back in late-2006, I started taking Ambien and was on it for 3 1/2 years. That stuff will knock you out quick. Then I moved and couldn't get it anymore. I really don't think it's addictive; however, after three years, I noticed I started to forget things. It was very noticeable, so I wasn't too bummed out when I couldn't get it anymore.