Where does the book Black Box by Julie Schumacher take place?

The main setting of Black Box is a psychiatric hospital, where the narrator's sister, Dora, is a patient.
Dora has depression and had to be admitted to the hospital after swallowing pills in an attempt to commit suicide. The narrator—Elena—and her parents visit Dora in hopes of "not saying anything that will upset her" and acting like "ourselves."
Although Dora is eventually released, the book continues focusing on the time within the hospital. Other locations in the book include the home of both Dora and Elena and the school where they are both students.
Since the book is focused on the hospital, it mostly describes Dora's experience, but it also describes how visiting Dora in the hospital affects Elena and the girls' parents negatively. Even though the hospital is meant to be Dora's saving grace, the visits to the location bring sadness and guilt to Elena and the parents.