I know it isn't neccesarily medically relevant, but what are dreams? Is there much research being done on this topic?
Like the previous poster said there are several different theories regarding the purpose/meaning of dreams. It seems as if most of the research has focused on the pattern or areas of brain activity during REM sleep and dreaming.
Here is a fairly recent article from Nature:
http://www.ncbi.nlm.nih.gov/pubmed/19794431