Green’s Dictionary of Slang

(US campus) a state of talking incessantly (and thus irritating others).

1997

K. Kainulainen ‘University Euphemisms in Calif. Today’ 🌐 ‘Braindead’ for a very stupid person or ‘talkorexia’ (someone who just cannot shut up has talkorexia) are all somewhat euphemistic, because they sound like diseases which you cannot do anything about yourself.