The narrator in "The Yellow Wallpaper" likely suffers from postpartum psychosis. Beginning soon after the birth of a child, symptoms can include depression, hallucinations, severe confusion, and paranoia. We know that the narrator has an infant and that she doesn't want to be around him:
And yet I cannot be with [the baby], it makes me so nervous.
The narrator talks about her "nervous troubles" that are "so depressing." She mentions that it is becoming difficult for her to "think straight" and mentions episodes of crying. And, of course, she begins to believe that there is a woman trapped within the patterns decorating the wallpaper in her room.
These symptoms keep intensifying as the story progresses, and she considers jumping out of the window of her upstairs room for exercise. The narrator comes to believe that this woman somehow escapes from the wallpaper during the day:
I see her in that long shaded lane, creeping up and down. I see her in those dark grape ' arbors, creeping all around the garden.
I see her on that long road under the trees, creeping along, and when a carriage comes she hides under the blackberry vines.
The narrator encompasses a great many symptoms that point toward postpartum psychosis. She realizes that the assistance her husband tries to give her isn't her best bet but is fairly powerless to change the dynamic and, thus, her treatment. Because of this, it seems that her id is constantly being repressed by her conscious. As she faces ongoing conflict between the two, her id slowly takes over, trying to stake out claims where it can when her husband is not around.
The husband's greatest fault is likely ignorance of medical conditions of that time period. While postpartum depression and even psychosis are commonly discussed in our society, these were not conditions commonly diagnosed during this time period. The proper treatment, including antipsychotic medications and mood stabilizers, also were not available at this time—though some other remedies likely could have helped.
Yet the husband insists that he knows best what his wife needs in the weeks and months after having a child, when she is clearly struggling. He believes that she needs to be completely alone and to avoid work. She tells him that she longs to be outdoors and to socialize with people. She longs to write, though she finds it exhausting. Yet she is dismissed, and her husband seems confident that he knows better than his wife how to heal her soul. Instead of putting his faith in his wife, John puts his confidence in Dr. Mitchell. This could be due to transference. John has attributed weakness and confusion to women and therefore to his wife. He has attributed knowledge and power to males and therefore to his wife's doctor.