All I wanted to say with my comment was that metaphors for mental illness aren't that uncommon in Japanese media. Tho I agree there is a very noticeable stigma around mental health in Japan. Anyway, on to my examples:
NGE was about people distancing themselves when they should try to connect with others. Depression played a role but it wasn't used as a metaphor.
Quote taken from
Wikipedia:
"Evangelion has long been taken as a deeply personal expression of Hideaki Anno's personal struggles and his long battle with depression."
I have no idea what you think in Meguca was metaphorical for mental illness
The whole series is at it's heart the opposition of hope and despair, and by extent, serves as an allegory of real-life depression, and it's quite poetic. Just take a look at the backgrounds, scenery and lighting.
Rascal was more personality issues.
Japanese media prefers to symbolize stuff like emotions, personality, and aspects of the human condition rather than any clinical mental disorder.
All of them have mental illnesses.
Kaede seems to have dissociative fugue.
Mai is depressed.
Futaba suffers from separation anxiety and self-deprecation.
Koga has an obsession with her view of a perfect life.
Nodoka has generational trauma caused by her mother and an inferiority complex towards her sister.
