Given the fact that the discussion about the ([neuro]biological) relevance of dreaming and consequentially dream content is still controversial (see, e.g., the works of Allan J. Hobson), you could perhaps find some hints here:
1: Pagel JF. What physicians need to know about dreams and dreaming. Curr Opin Pulm Med. 2012 Nov;18(6):574-9. doi: 10.1097/MCP.0b013e328358bf42. Review.
2: Stumbrys T, Erlacher D, Schädlich M, Schredl M. Induction of lucid dreams: a
systematic review of evidence. Conscious Cogn. 2012 Sep;21(3):1456-75. doi: