Ooo! Ooo! Ooo!! I can answer this one!!

So the concept of female hysteria goes back as far as ancient Greece. Plato speculated^1: That a uterus would "blocking passages, obstructing breathing, and causing disease" .

Hysteria was literally the "Catch all" for diseases that women experiences (many of the "symptoms" of Hysteria are now recognized as schizophrenia^2 , boarder line personalitly disorder^3 , conversion disorder^4 (This disorder is slowly dispersing and being replaced with neurological diseases), and anxiety attacks^5 ).

Incredibly popular during Victorian times. I was thought that one quarter of all women suffered from "hysteria^6 ". Laura Briggs, who wrote the article "The Race of Hysteria: "Overcivilization" and the "Savage" Woman in Late Nineteenth-Century Obstetrics and Gynecology^6" summed up your question nicely with this:

As a disease of "overcivilization," hysterical illness was the provenance almost exclusively of Anglo-American, native-born whites, specifically, white women of a certain class. Second, the primary symptoms of hysteria in women were gynecologic and reproductive -- prolapsed uterus, diseased ovaries, long and difficult childbirths -- maladies that made it difficult for these hysterical (white) women to have children. As such, hysteria also implicitly participated in a discourse of race and reproduction, one which identified white women of the middle and upper classes as endangering the race through their low fertility, while non-white women, immigrants, and poor people had many children.

So yes, "hysteria" primarily affected the middle and upper classes while the poor working class women didn't (typically) "suffer" from this "disease"!

All I have to reference is a play named "In the Next Room/the Vibrator Play" by Satah Ruhl, the history the program gave me about the treatment of hysteria, and the one lecture I attended: http://en.m.wikipedia.org/wiki/In_the_Next_Room_(or_The_Vibrator_Play) (on mobile, cant hyperlink)

While any woman could be diagnosed with it, those of middle and upper were the majority of those treated. One character mentions how the wife does nothing all day, which probably causes the hysteria to worsen so she requiers more frequent treatments. In the lecture it was agreed on that those of lower class were too busy with children, housekeeping and scraping by with what little money they had to waste time at a doctors. While ladys were getting restless especially during the Victorian era, wanting more out of life than the standard lifestyle for young upper class women. A restless women/one seaking a life that we would now consider normal, would be concerning for her family or husband, resulting in a vast number of women being diagnosed with hysteria.

TL;DR: the poor are too poor for any doctor treatment, especially something like hysteria. And Ladies need to be calm and collected, none of those equality thoughts!