From The Guardian:
Poets, by tradition, imagine themselves likely to die young. But that's not a matter of imagination, says Associate Professor James C Kaufman, of California State University at San Bernardino. It's a simple fact.
Kaufman looked at the lives and deaths of 1,987 deceased writers from four different cultures: American, Chinese, Turkish and eastern European. His 2003 study, The Cost of the Muse: Poets Die Young, paints a mathematically ghoulish picture. Poets drop off earliest, Kaufman explains, but authors in general are not a long-lived bunch.
He writes that: "The image of the writer as a doomed and sometimes tragic figure, bound to die young, can be backed up by research. Writers die young. This research finding has been consistently replicated in a variety of studies."