I was studying Psychology (to be a therapist), but I switched majors. I'm in early childhood education now. I do think I'd like a degree in Psychology eventually, if only because I've heard it can be useful when working with children in advancing in that field. I'm fairly certain that, over the years, I've seen other psych students on these boards as well. Whether I have seen therapists/psychiatrists/anyone with at least a bachelor's or master's degree in psychology... I don't recall.

I'm sure they do read the threads sometimes. I'm sure they get curious to know the things their patients might talk about when you remove the face to face interaction (many tend to be more honest online). I know, as a psych nerd, I do. Whether they're active or not, I don't know. Probably? I guess. I'm not sure they'd "out" themselves, but even therapists can have depression, anxiety, etc. Important thing to keep in mind.