Japanese Literature and Suicide: Is There a Correlation?

Mel, of The Reading Life, has read fourteen books for the JLC3 already. We're barely half way through, and I think he's devoured more than anyone so far.

He asked a question today, though, for which I have no answer. I'm posing it here in case someone else does:

I have read works by 14 Japanese writers for the challenge-it seems about 1/3 of
them have died by suicide-any thoughts on this?

If you know the answer, or think you have an idea, please leave your thoughts in the comments. It's an intriguing question, and one suitable for this time of year when ghosts and ghouls and ideas about death seem to abound.