On Dr. Arthur C. Jacobson’s 1926 work Genius: Some Revaluation, in the current BMJ (subscription required):
Jacobson goes on to write that the great external midwives of genius, especially in its literary forms, are alcohol and tuberculosis…This is the famous “spes phthisica,” the euphoria of the dying tubercular patients, so well known to opera but not so well known, apparently, to doctors…In 1940 Jacobson was quoted in Time: “The decline in TB coincides with the decline in creative writing.” There could, of course, be other reasons for our literary impoverishment.