The case of Nobel Prize winner John Nash presents an interesting platform for exploring the nature of mental illness. Winner of the Nobel Prize in Economics in 1994 for his contribution to game theory, Nash had suffered from paranoid schizophrenia much of his life.
Nash's life was depicted in the 2001 film, A Beautiful Mind, which took considerable dramatic license with his story (although still a good film, in my opinion).
For a more realistic consideration of his illness, treatment, and remarkable recovery, check out the American Experience documentary, A Brilliant Madness. The companion site features bios, extended interviews, and a timeline of mental health treatment.