i'm looking for a movie to watch...
similar to secret window, or just one that focuses around the life of an author/writer,
or,
someone with a mental illness, depression, bi polar, insomnia, a psychological one,
There is Misery. It is also a movie based off a Stephen King book, a lot of his books involve a character who is an author. Misery does not have a deranged author (there is an author present, but not deranged), but a deranged fan of an author.
it is also about a deranged author. and it is also by Stephen King