I wrote an article regarding dopamine as well, I saw a couple recently on HN on the subjects of dopamine and self discipline, if you guys are interested. Much more in depth than the articles I've seen make it onto HN - but I didn't really think this was the appropriate place for them, that's why I never submitted them. Kind of off topic IMO, but for readers who like it here they are:
Dopamine, rewards, pleasure center of the brain -> http://sidsavara.com/personal-development/personal-developme...
Willpower research -> http://sidsavara.com/personal-development/will-power-how-to-...