What is the father's illness?

You never find out, they never tell you in the book either, don't know why, maybe the author had her own idea of his illness that didn't fit with any actual diagnosis.

From what I understand, he had a heart condition and that is why he ended up in the hospital. It is not unusual for people that have had heart problems to worry about dying. They are afraid to go to sleep, afraid to do most things that might cause the condition to worsen. When Gray tells Smith "He is afraid he is going to die" I came to this conclusion.

The doctor says clearly that he doesn't need a cardiologist, he needs a psychiatrist. The mother talks about his medication not working when he buys into crazy ideas. Clearly, his problem isn't physical, or at least if it is it manifests as a mental illness. He seems paranoid and delusional - maybe schyzophrenia?


"I'll book you. I'll book you on something. I'll find something in the book to book you on."