I heard David Linden, author of The Compass of Pleasure (http://www.amazon.com/Compass-Pleasure-Exercise-Marijuana-Generosity/dp/...), talk on NPR (http://www.npr.org/2011/06/23/137348338/compass-of-pleasure-why-some-thi...). Sex addiction in particular came up. He doesn't think there are many sex addicts because as long as a person gets pleasure they are not an addict. That doesn't sit right with me. Linden might be qualified and well-intentioned, but he seems to be missing something. He also describes himself as having a not very addictive personality while being a hedonist who has to spread out his vices, presumably so as not to become addicted. That alone suggests to me that he hasn't fully integrated all that he could into his own life. I also question this distribute your vices model. Dopamine is dopamine. Does it matter how it gets to the brain if it is still getting there in large quantities?