If you've ever taken a depression screener at a wellness visit, that's a consequence of this work. This paper describes how unreliable psychiatric diagnosis used to be. There were standards, but they ultimately came down to physician judgment. This created demand for more objective standards, which resulted in the "checklist" approach that we have now.
It's true. You wouldn't believe how many people I've SIGECAPS'd during my medical training. I didn't realize this article was the beginning of this approach, but it certainly helped get care to people who previously wouldn't have received it. Though I'm sure there are also many who may require intervention that aren't captured by a SIGECAPS exam. The double edged sword of the checklist manifesto, though I overall think it has been beneficial.
SIGECAPS is an acronym taught in US medicine for the diagnosis of major depressive disorder: Sleep disturbance, Interest loss, Guilt, Energy loss, Concentration loss, Appetite changes, Psychomotor agitation, Suicidality. And must have Depressed mood or Anhedonia (inability to enjoy things previously enjoyable).
The history of the SIG E CAPS acronym is also interesting, I've heard it was short for SIG (old shorthand for "to be prescribed") Energy CAPsules.