Here's at least one psychiatrist who contends that Gen. Sherman was bipolar -- Nassir Ghaemi, psychiatry professor at Tufts medical school.
In his 2011 book, A First-Rate Madness: Uncovering the Links Between Leadership and Mental Illness, Ghaemi in his introduction admits that it's problematic to diagnosis someone posthumously:
"Retrospective psychiatric diagnosis is fraught with risk and never definitive." (Page 2)
But he does it anyway, maybe because that's kind of the whole basis for his book. Here's some of what he says about Sherman in his introduction:
"Historical evidence suggests that Sherman suffered from manic depressive illness, or bipolar disorder—extreme shifts in a person’s
mood, energy, and ability to function. Someone need have only one manic episode to be diagnosed as manic-depressive; in fact, most people with the illness suffer mostly from depression. In addition to the Kentucky breakdown, Sherman apparently had at least four other major depressive episodes, the first at age twenty-seven, with symptoms of hopelessness, inertia, insomnia, and loss of appetite. He’d been having trouble settling into a military career and feeling excessively controlled by his father-in-law. The second episode occurred around age thirty-seven, when Sherman was a struggling banker. Another followed a few years later, again involving financial hardship. Another, at age fifty-eight, thirteen years after the war, came after his oldest son, Tom, a deeply depressed and sometimes homeless man who ultimately died in an institution, refused to study law, as Sherman desired, and decided instead to become a Jesuit priest." (Pages 1-2)
Ghaemi actually thinks that mental illness can enhance productivity and creativity:
"I focus on historical leaders because, as a psychiatrist, I am eager to understand the benefits, as well as drawbacks, that can accompany mental illnesses. Clinical research has demonstrated these benefits—resilience, realism, empathy, and creativity. Yet most people haven’t taken much note of this research. Showing the link between these strengths and madness in several of our most celebrated leaders could raise our awareness about the strengths that some mental illnesses can bestow on anybody who suffers from them." (Page 10)
Looking at reviews of his book, I see that Ghaemi definitely has his critics. All the same, it's interesting to see what he has to say about Sherman.
Roy B.