American headache through the decades: 1950 to 2008.

As the American Headache Society approaches its 50th anniversary, it seems worthwhile to step back and survey the many changes in the headache field since the 1950s. Many, perhaps most, of the trends, ideas, and changes we review in this article cannot easily be assigned to a particular decade but we have nonetheless chosen a by-the-decade format because it is a familiar and useful way of understanding history. Our focus is on events in the United States and the American Headache Society; space and the need to limit the scope of the article preclude a full description of the many parallel and influential trends, personalities, and ideas in other parts of the world or in other professional organizations. The authors hope you will find this summary of American Headache Medicine in the last half of the 20th and the beginning of the 21st centuries entertaining and educational.