The Victorians had little understanding of the true nature of mental illness, and I think every melodramatic Victorian movie has the scene where one of the characters is dragged away to the insane asylum. The so called "treatments" that patient's were subjected to were pretty horrific. Here are some links on the subject:

Women's Mental Illness- What women were subjected to in the name of science. There are a few typos, but there is a respectible bibliography cited at the end of the article.

Bertha Mason's Madness in a Contemporary Context - Charlotte Bronte's Jayne Eyre features a madwoman locked away in the attic...

The Fasting Girl- A review of a book describing a case of a famous Victorian anorexic.

Bethlem Royal Hospital- England's hospital for the insane, better known as Bedlam.