Whenever mental hospitals are mentioned, the general impression is one of high walls, iron-locked gates, gloom, dimness, strict terror, and an omnipresent sense of being "caged in."
The patients are often unkempt, disheveled, babbling nonsense, raving mad, while the nurses are burly, wielding electric batons, and the doctors do little more than prescribe sleeping pills and tranquilizers.
Well... this perception, aside from being perpetuated by various artistic and film representations over the years...
Is mainly because mental hospitals a century ago really were like that, or even worse.