The Daily Telegraph had, the other day, a long article commenting on a Russian woman who had murdered a little girl. A Dr. Balinsky prevailed upon the jury to give a verdict of acquittal, because she was a "psychopath." The Daily Telegraph regards this term as a new coinage, but it has been long known amongst Spiritualists, yet in another sense. ["The Medium and Daybreak," Jan. 16, 1885]
The case alluded to, and the means of acquittal, were briefly notorious in England and brought the word into currency in the modern sense.
Then crept in the "loose" usage. Anybody who wrote or spoke about public affairs came to be dubbed a publicist. It was only a question of time when the dam would give way and the word flow in all directions and be made to cover every kind of talent, or lack of it. ["The Nation," Nov. 22, 1917]
Meaning "press agent" is from 1925 (publicity agent attested by 1900); publicitor also was tried in this sense.