You are free to disagree, I guess.
The doctor was going through a premature mid-life crisis, but not the kind where one buys fancy cars and tries to listen to popular music. He was anxious and frustrated. In order to promote an overall feeling of despair in is waiting room, he replaced the aquarium with a snake cage, in which he placed a model of a human skull. And on the walls, he hung various renditions of The Scream.