Josef Breuer and Sigmund Freud did work together and they did collaborate on a book about Anna O, who was most likely Bertha. Lou Salome did have relationships with Nietzsche and Freud and many others. All of these things are true.
But, Breuer did not treat Nietzsche. That is in the author's (Irvin D. Yalom) imagination, and what a great imagination it was. The story makes a super philosopher seem human, with frailties that we all suffer. It also makes for an interesting story of how psychoanalysis came about. I can imagine that it really did develop this way as Breuer and Feud discovered what worked and what didn't. We see free association or "chimney sweeping" as Bertha called it, we certainly see transference, and much more as the discipline developed.
Ben Cross was excellent, Armand Assante gave the best performance I have ever seen from him, Jamie Elman let us see Feud as a young man, Katheryn Winnick certainly makes me want to see her again, and Michal Yannai was delightful.
A great period piece that will delight all who care about philosophy and psychology.