is there an anime that tackles suicide/depression.

I'm looking for a sad anime, something as the title depicts, being alone, depression and one that doesn't have a happy ending. yes I'm okay. i am just wondering if there any shows that tackle this subject.

EDIT: wow this post absolutely blew up thankyou all so much ❤️ I think I am set now though after almost 800 suggestions 🤣

You are all beautiful people have an amazing day