Sorry to raise such a morbid topic, but I've been wondering and
haven't found any information on point.

Suicide is a leading cause of death in the U.S. (especially my current
home state of Nevada) and in Japan. Is suicide known at all among
traditional hunter-gatherer societies? If so, what is the incidence?

Even the ancient Greeks described melancholia, so it's not strictly a
feature of modern life. However, it may be a feature of a structured
society, where everyone _must_ find a place within the structure. I
suspect that modern life is so structured that many more people break
under the strain. Perhaps in an HG society, just about everyone can
fit in one way or another.

Bill