I often get asked what ‘nervous breakdown’ means, as if it was a technical term defined by psychology.
In fact, it’s really just an everyday term used to describe when someone can’t carry on because of psychological problems, although it turns out to have quite technological origin, as this brief article from the American Journal of Psychiatry describes.
The Cambridge academic German Berrios (personal communication) informed me that “breakdown” is a 19th century construction, initially used to refer to breakages and fractures in machinery and leading to the need for “breakdown gangs” (i.e., teams of navvies whose job involved addressing the mechanical disruptions to the functioning of railways). Metaphorical uses of the term followed, particularly in reference to failure in personal intentions and plans.
Berrios suggested that it was only in the second half of the 19th century that its metaphorical connotations were extended to the brain—and later to the mind. Its initial association was not to depression, anxiety, or psychosis but to symptoms associated with mental and physical exhaustion and relating to 19th century constructs such as “neurasthenia,” “the vapors,” “spinal irritation,” and “nervous prostration.” Because neurasthenia (in Greek meaning “lack of nerve strength”) imputes a physical basis (in the nerves) rather than psychological weakness, it was an intrinsically less stigmatizing phrase than “mental illness,”
Link to AJP piece on the ‘nervous breakdown’.