Actually the doctor is smart. He saw how stupid Lan was and dollar signs flashed up where his eyes should be. He can milk this total moron for $50k by just playing along with his delusions.

“HMM, yes I see. So you eat like shit, have no sexual or life partner, no job, no responsibilities, don’t go outside and have no purpose in life? This is going to require a very extensive list of very expensive medications to fix.”