Wild question
This is a completely loose question. Nowhere near a hypothesis. More like a "Hmm. That's odd. I wonder if...."
Was listening to BBC interview with some young journalist type who was describing her struggles with suicidal urges. She was, of course, speaking in glottal fry and using carefully limited vocabulary.
Youngsters who have gotten locked into bad thought patterns always talk in glottal fry. That's not the question. It's an obvious correlation.
Glottal fry and careful word choice are two types of self-censorship, acoustic and lexical respectively.
I remember my own hippieshit days. Glottal fry wasn't a fad then, but the same word-choice syndrome was present. When I was talking with an adult about political matters, I always chose my words carefully.
Important point:
This is not fearful self-censorship. This is arrogant self-censorship. I did not want to sully the Party-code words by letting them enter the unwashed ears of a fascist.
Glottal fry is the same thing on an acoustic level. This journalist doesn't want to sully her full voice by letting it enter the unwashed ears of fascists.
Now. Here's the wild question.
Does this correlation work both ways? By speaking in self-retracted modes, both lexically and acoustically, are you causing your self to retract?
Or putting it much more simply: Full-voiced people, even
annoyingly LOUD people, do not commit suicide. Can you break out of a downward spiral by talking loud and firm? By sounding authoritative?