I'm interested in locating either assorted texts or a particular female historical figure who produced any kind of writing during or around the time of their involuntary committal. Thank you!
Given that you specified involuntary, I take it you might already know if this source, but I'll run it past you just in case.
Nellie Bly, who was an American journalist, feigned insanity at a women's boarding house so that she would be committed to Blackwell's Island asylum for women in New York. She published a book about her experience in 1887. It was titled Ten Days in a Mad-House.
The closest I've seen to involuntary inmates' writings is the odd newspaper published in an asylum by the inmates. Here is one example- I'm sure I've heard of others, but I can't recall them off the top of my head. I'll make a note to get back to you if I do.
Hope this helps in your search!
What about "The Yellow Wallpaper" by Charlotte Perkins Gilman. She was forced to be trapped in one room for months by her psychiatrist, and that is her fiction about that time.