Nevertheless, I emphasize that one needn't agree with the claim to realize that the adherence effect is quite general. The point is methodological, not medical. Moreover, instances of it might help explain the efficacy of belief and adherence in many realms other than medicine, drug testing, and college admissions.
A notable example is religion, where other enhancers of the placebo effect, such as a recognized "brand" and dispensation by an authority figure, also play a role.
John Allen Paulos, a professor of mathematics at Temple University, is the author of the best-sellers "Innumeracy" and "A Mathematician Reads the Newspaper," as well as "Irreligion: A Mathematician Explains Why The Arguments for God Just Don't Add Up." His "Who's Counting?" column on ABCNews.com appears the first weekend of every month.