Anime/Manga about Depression..
 

Are there any?

Neia_7, Haibane Renmei, Neon Genesis Evangelion

What exactly do you mean? Because you can find depression in any drama.

Neon Genesis Evangelion

Ano Hana

Full Metal Panic: The Second Raid

The Melancholy of Haruhi Suzumiya :D

H2O: Footprints in the Sand Episode 12

It maybe 12 episodes but I fudging love it You should try it out and maybe Clannad And
Clannad After Story more after story thou hmm let me see what else

Kanon (2006)
Mushishi

Those are pretty depression but i mostly Recommend Clannad after story and H20 MY Favorite anime EVER!!! (Drama wise)

I enjoy watching anime's that are depressing. The best one's that I have found so far are
sora no otoshimono- this one and it's sequel have some depression in it
ayakashi- the depression in this one becomes clear about half way through the series
Ga rei zero- WOW this is one amazing anime in my opinion. It starts off kinda different from other anime's but its all worth it at the end lots of despair in this one.
Madoka magica - some depression
kurokami- not so much depression some sad scenes but the ending is kind of sad and happy at the same time.
saikano- The first couple of episodes had me bored but it was truly worth it. This was a great anime
Destiny of the shrine maiden- Everything becomes clear at the end of the anime.

I highly recommend Ga rei zero though if its a depressing anime your looking for this anime can sure deliver it to you.

seconded Puella Magi Madoka Magica :rolleyes:
and
Ef for both season...

All the characters in Welcome to the NHK! suffer from a variety of psychological disorders, but one of main supporting characters, Kashiwa, is obviously a depressive and paranoid to boot. For most of the show she's a walking pharmacy carrying a range of psychiatric medications.

Next, I'll suggest the opening story in the anthology Aoi Bungaku, a retelling of the famous Japanese novel, Ningen Shikkaku ("No Longer Human"). The main character and a woman he encounters considers suicide as an escape from their depressions.

Kuuchuu Buranko ("Trapeze") is an episodic tale about an unconventional psychiatrist and the various patients he treats. The patients display a wide variety of disorders, though I'm not sure that any are depressives per se rather than simply being depressed as a consequence of other conditions.

The main character in Ghost Hound suffers from post-traumatic stress disorder as a consequence of being kidnapped with his sister when he was very young. Again it's not clear whether Tarou is also clinically depressed, or simply deeply unhappy and disturbed by these events.

I watched Ga-rei ZERO like a week ago and I'm still depressed about it. :upset:

Colorful. A magical realism tale about a 14 year-old boy who attempts suicide. Highly recommended.

I can understand it has an incredible story with a lot of depressing circumstances that occur. I really wouldn't mind if they made a second season from the manga.