Also appearing in the New York Times Upshot column, this Incidental Economist blog post on the prevalence of depression, addiction and suicidal thoughts among doctors provides a great overview of the literature.  The post is also compelling because the author draws on his own personal experience with this condition during his own residency, including this moving post about secondary trauma experienced (repeatedly) by many physicians.

Source: Silence Is the Enemy for Doctors Who Have Depression

Please see my related post on prevalence of depression among medical residents here.