Some things talked about (or can be seen) include:
Mental health, physical health, medication and medical related things, psychosis, odd or confusing talk, delusions, hallucinations, death, suicide/suicidal thoughts and just stupid teenager talk.
Everything else isn't fundamentally "upsetting". If you don't like that then you obviously don't have to read any of it. Also, don't read these if you're a family member of mine.