Some of these language patterns sound like the person is aware they have a personality disorder or some sort of behavior problem. That’s probably good.

Though, they do say “these patterns aren’t usually deliberate”.

But even being aware may not mean you really deeply understand why you have a problem.

Active and passive voice can also be a pattern among others but obviously not a disorder on it's own - more like an insight into viewpoint or thinking

"I was kicked out of the conference by the organizers"

"The organizers kicked me out of the conference"

and

"He was kicked out of the conference by me"

"I kicked him out of the conference"

> If someone’s messages suddenly become unusually urgent or extreme, emotionally negative, absolutist, inward-focused and socially detached, it may be a sign they’re struggling.

No shit.

> Those with darker personality traits often use more hostile, negative and disconnected language, including more swear words and anger words, such as “hate” or “mad”. At the same time, they use fewer socially connected terms like “we”.

People who want and choose to view your words uncharitably will do so regardless of what you say. For example, the use of “we” could also be seen as narcissistic or imperial. Managing the sensitivities and psychological state of the reader and observer is the greater part of social interactions than managing your own states.

Can't wait for this to be wrapped up in a neat detection algorithm, with about the same efficacy rate as the college plagiarism detectors and the LLM writing detectors.

Illustration of Simpson's paradox:

                      personality disorder w. negative language   no disorder w. negative language
  total                                992    75%                         945    25%

but actually

                      personality disorder w. negative language   no disorder w. negative language
  had a rough time in life             909    80%                          79    80%
  had a decent time                     83    20%                         866    20%

(Figures made up.)