The New York Times has an excellent article on the history of the ‘nervous breakdown’ – an inexact term that has never been officially recognised but which has been popular for over a century.
The article suggests that the phrase is common precisely because it sounds medical and, hence, significant, but remains vague enough to be used flexibly and by everybody without seeming pretentious.
The vagueness of the phrase made it impossible to survey the prevalence of any specific mental problem: It could mean anything from depression to mania or drunkenness; it might be the cause of a bitter divorce or the result of a split. And glossing over those details left people who suffered from what are now well-known afflictions, like postpartum depression, entirely in the dark, wondering if they were alone in their misery.
But that same imprecision allowed the speaker, not medical professionals, to control its meaning. People might be on the verge of, or close to, a nervous breakdown; and it was common enough to have had ‚Äúsomething like‚Äù a nervous breakdown, or a mild one. The phrase allowed a person to disclose as much, or as little, detail about a ‚Äúcrackup‚Äù as he or she saw fit. Vagueness preserves privacy.
As the article notes, we have a long history of vague ‘emotional exhaustion’ coveralls stretching from neurasthenia to burnout syndrome that come in and out of fashion.
Link to NYT On the Verge of ‚ÄòVital Exhaustion‚Äô?