How Tanning Changes the Brain - NYTimes.com
http://well.blogs.nytimes.com/2011/08/12/how-tanning-changes-the-brain
Scientists have suspected for some time that frequent exposure to ultraviolet radiation has the potential to become addictive
(...) the research was inspired by a colleague, based on her experiences with dermatology patients. “She approached me because of her concern about young adults who were coming to see her with these beautiful bronze tans,” he said. “And she would cut out skin cancers, and they would immediately go back to tanning.”