One Flew Over The Cuckoo's Nest/I'm the King of the Castle

Hello, for I am new here I apologize if I posted in a wrong forum.

I have to find a topic for my thesis on these two works (it should be a kind of comparation between them):
- Ken Kesey's One Flew Over The Cuckoo's Nest
- Susan Hill's I'm the King of the Castle

Those who have read the two novels, can you suggest a common theme/topic? Can you see any similarities between the two books?
What I had in mind:
- the roles of the protagonists/antagonists
- the battle between good and evil
- the abuse of antagonist's power

Anyone, please? I would be really grateful for your opinions, suggetions. Thank you so much!

What am I missing? Is this a joke comparison? I don't see the connection between the two pieces.