I'm curious as to how it was adopted by countries for which English is not the primary language. I remember being surprised when I heard Parisians using it regularly in their speech.
For one, it's an easy pick for someone with a cosmopolitan spirit. Then there's also a lot of gadgets or software that come with the untranslated "ok" which serves as a pushing base for all but the most aware and opposed to the adoption of foreign words.
Have heard somewhere else this was widely spread in WWII era or thereabouts since it was good for radio communications and there were many USians around
I couldn't help but think of a drug user's eagerness to attach deeper meaning to seemingly unimportant events while under the effects of heightened dopamine levels.
Only by a small portion of the psychiatric community. The vast majority believe that the causation runs the opposite direction, that it's self-medication. This has been discussed for years for just about every serious mental illness, in fact. There's no real consensus either way, but most mental health professionals I know agree with this.
(I grew up in a house of mental health professionals, so I've had no dearth of opinions on the matter, to say the least.)