I have also lost the ability to dream. It all happened when I lived with my sister. I smoked pot a few times, and drank alcohol a few times, and smoked/still do smoke cigarettes. My most vivid dreaming experience happened when I woke up from sleep and I couldn't talk or move. I tried yelling to my sister. And I couldn't. After that it was just bad dream until it went away. Some really scary stuff. I was taken under the bed in one, and it really felt like someone was trying to pull me under there. I had that sleep paralysis about 3 times in my life. I kept dreaming bad dreams. I dreampt once someone was growling at me from inside my head, and so I was growling in reality. I also dreampt that King David or someone that looked just like him (and my first thought was I am meeting Satan in my dreams). His castle was made of dolls that looked grotesque as paintings. And suddenly my feet were being thrown in midair and I was being dragged in circles. Eventually I was not dreaming at all.