ok, so heres what i'm thinking, the release of certain chemicals in the brain such as dopamine and even something like adrenaline can be controlled by the mind, so technically if you could will your mind into releasing some of these chemicals, you could get some of the same effects as if you were to do a drug only without all the negative side affects. I'm sure that you could convince your brain to do this in a dream, so then my point is this. When you do a drug in real life, you get addicted to it because your brain likes the feeling of these chemicals being released, and it know that it will happen only when you take that drug. That is why you crave it. Let's say that you were to release these chemicals in a dream, would you technically then become addicted to lucid dreams? cause that is the action which results in the "good feelings." This could help people having trouble with LDing, and then it might even happen every night!