One topic I did an interesting study on in my earlier years was comparing the artistic expressions of various mental pathologies. To little surprise, the art created by schizophrenics was the 'busiest' and most provocative of the lot. I wasn't able to locate any of the pieces I used back then but I did find some equally impressive ones now. The first series is from artist Karen Blair, who also has a blog. She has catalogued her gallery corresponding to the years she was on particular medications. In order of Risperdal, Zyprexa, and Seroquil:
Electricity Makes You Float
What Jack Saw
These paintings are from a website put together by a father for his son John. It's also a touching chronicle of his perception of his son's illness. As dazzling as John's abstract paintings are, most impressive is the detail in his faces.
From an exhibit at the History of Medicine In Lund, Sweden, here are a few pieces from patients of the pre-psychopharmacological drug era. Works from Maria Magdalena Rudbeck, Rudolf Persson, and Clara Miranda Almér are shown here:
From Erik Lombardo I discovered William Kurelek and Louis Wain, two artists who came across schizophrenia at different stages of their lives. Kurelek's onset was early and he was able to overcome his torment - this page has terrific samples from his remarkable descent into madness and back. Here is one of his more popular pieces - The Maze:
Louis Wain was a popular postcard and children's book illustrator known for his cats. Unlike Kurelek, Wain developed schizophrenia later in life and was never able to recover. Two before and after pieces show the changes in the artist:
During my research I found this oddity in Wikipedia's entry on schizophrenia. Look at the end of the third paragraph. I took a snapshot before the page gets edited as I don't think it will remain: