Dark Anime Recommendations

Been busy with school, life and such... and a bit of Minecraft (the Japanese build is coming on steadily, I'm happy with it so far-will send screenshots upon request although it's not much).

Anyway, I recently found an AMV on YouTube called Reflections of Despair (by Gigguk), which is the most accurate depiction of what someone can think when things get really bad... admittedly I have felt exactly the same way before... not good times. Anyway, go watch if you haven't-it's really well made!
This AMV made me want to watch some less-than-happy animes and read maybe a couple mangas of the same demeanor. So suggestions on any animes/mangas that are on the dark or mentally unstable side would be appreciated ^^ Not to worry-my mentality is currently fine so you won't be fueling something bad by suggesting. I'm just interested.

Hope you're all having a great time!
-Haitaka

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