David Brin contends that "self-righteous indignation" is a sort of "drug high":
We’ve all been in indignant snits, self-righteous furies. You go into the bathroom during one of these snits, and you look in the mirror and you have to admit, this feels great! "I am so much smarter and better than my enemies! And they are so wrong, and I am so right!" And if we were to recognize that self-righteous indignation is a bona fide drug high, and that yes, just like alcohol, some of us can engage in it on occasion — as a matter of fact, when I engage in it, I get into a real bender — but then say, "Enough." If we were to acknowledge this as a drug addiction, then it might weaken all the horrible addicts out there who have taken over politics in America, and allow especially conservatism to return to the genteel, calm, intellectual ways of Barry Goldwater and William F. Buckley.
You can read Brin's talk on the subject at the National Institute for Drug and Addiction here.