Thanks for pointing out the information about depression, Marion. In addition, much more is known about it today than in the 19th century. They called it "melancholia," and some of the treatments for it would be considered barbaric today. DQ touched on the subject in "Before the Dawn."
In my stories, I have depicted Sully as suffering from it at times. Today, we have numerous medicines to treat it, but strange as it seems, in those days, they would perform ovariotomies to treat "Menstral Madness," a form of insanity! Today we call it PMS.
Debby K