The way that Mrs. Dalloway portrays mental instability is really interesting. Seeing the world through Septimus’s eyes is fascinating in and of itself, but the way the world around him deals with his mental illness is even more compelling. Rezia’s attempts to reach him fail, or at least seem to have failed thus far, but she seems to be making a genuine, concentrated effort. We also get to see how his illness affects her life; she feels alone and helpless, and even seems to resent him, all while never losing her sincere desire for his wellbeing. 

The way the doctors treat him is another interesting look at how mental illness is perceived. Dr. Holmes and Sir William Bradshaw deal with Septimus in drastically different ways, but neither of them seem like they’re going to help. Holmes simply insists that there’s nothing wrong, and Bradshaw, while acknowledging that Septimus is ill, seems as if he does not truly understand how to help. He merely asserts that Septimus lacks “proportion” and uses him as an opportunity to exert power.

The way that various characters interact with Septimus provides an interesting commentary on the way that post-war England dealt with mental illness. Or really, the way that it didn’t.