The New York Times has a small piece discussing the history of the notion of “the nervous breakdown.”  Quoting historians Peter Stearns and Edward Shorter, the article notes that the term’s persistence and popularity, in large measure, has derived from its relative vagueness as well as its apparent lack of medical connotations.  The history of what counts as “vagueness” and “precision” in clinical nosology, diagnosis, and prognosis at any given time is an issue worthy of closer empirical study.  For those interested in pursuing this further, have a look at the article by Barke, Fribush, and Stearns, “Nervous Breakdown in 20th Century American Culture.”