Maybe I give people benefit of the doubt a bit much, but spaces online also include people who are overseas... And how distribution of people in general online is really skewed, because of how easily accessible it is. You can always ask the same how many people have ADHD or autism, or something like that. While people may be faking, people may also just be mistaken.
That's my thoughts at least :p
(overseas compared to what? /genq)
i'd say much of the mental illness discourse stems from the fact that these online spaces are most often filled with 14-16 year old kids whose personalities and brains are rapidly developing which can be rather jarring to experience. added on top of this, they're part of a generation who's had access to unlimited information since birth by means of the internet, which makes it painfully easy to misdiagnose yourself with a mental illness.
i was a victim of this pitfall too ~4 years ago, so i can say with certainty that although there's undeniably a larger concentration of mentally ill people around here, a lot of them are just developing teenagers who haven't gotten differential diagnosis.
(in particular i misdiagnosed myself with adhd, which turned out to be a massive dead-end, and only through attending therapy with professionals was i able to be diagnosed with ocd, the actual root of my problems. if i hadn't known i don't have adhd, i might have had a very very different outlook on life.)