How is mental health and the importance of active patient involvement in their own treatment addressed in "The Yellow Wallpaper" by Charlotte Perkins Gilman?

To begin, the validity of the narrator's experience of mental illness is questioned by her husband, who is also her physician. She tells us in the opening paragraphs that he "laughs at [her]," and she expresses her belief that she does not get well more quickly because he "does not believe [she is] sick!" She asks, rather resignedly, "What can one do?" The narrator's illness is downplayed, and she is told that it does not exist; there is simply no way she would be asked to participate in a treatment plan because her doctor/husband is too busy trying to convince her that she is imagining her illness. Her husband, John, tells all of the narrator's friends and relations that she only has a "temporary nervous depression—a slight hysterical tendency," and her brother, also a doctor, says the same thing. Told that she is overreacting or making something out of nothing, she says,

I take phosphates or phosphites—whichever it is, and tonics, and journeys, and air, and exercise, and am absolutely forbidden to "work" until I am well again. Personally, I disagree with their ideas. Personally, I believe that congenial work, with excitement and change, would do me good.

Instead of being allowed to help determine the best course of treatment, however, the narrator is essentially locked into a room at the top of the house, forbidden to see family or friends—even when she specifically requests it—and prevented from employing her obviously intelligent mind by either reading or writing. The narrator's considerable vocabulary helps us to understand what a critical mind she has. For example, when describing the wallpaper in her room, she says,

I know a little of the principle of design, and I know this thing was not arranged on any laws of radiation, or alternation, or repetition, or symmetry, or anything else that I ever heard of. Looked at in one way each breadth stands alone, the bloated curves and flourishes—a kind of "debased Romanesque" with delirium tremens—go waddling up and down in isolated columns of fatuity.

In the absence of any other mental stimulation, this clearly intelligent woman is forced to ponder whatever is available to her: the terrible wallpaper. If she could devote her mind to the things that she enjoys, if she could read and write, or if her husband did not insist on "complete rest," then it seems quite likely that she would improve. One of the great ironies of this story is the fact that the "cure" actually makes her much more ill. Initially, she seems to have what we would now call postpartum depression, but, by the end of the story, she no longer recognizes her own identity and has taken on a fictitious new one that she has imagined. If this is the result of the "cure" suggested by the medical community, which never even validates the patient's own feelings let alone takes into account the patient's input about her treatment, we can only conclude that patient involvement is necessary in order to best serve the patient.