Considering that the global prevalence of mental health issues in the population is one in seven[1], that would make OpenAI users about 100 times more 'sane' than the general population.
Either ChatGPT miraculously selects for an unusually healthy user base - or "showing signs of mental distress in chat logs" is not the same thing as being mentally ill, let alone harmed by the tool.
[1] https://www.who.int/news-room/fact-sheets/detail/mental-diso...