There were several reasons for Patrick Dempsey's departure from Grey's Anatomy.
Actor Christopher Meloni abruptly left the programme in 2011, and he later gave an explanation, saying that his contract negotiations with the network failed after season 12.
Sophia Bush, an actress, at last discussed her departure on Dax Shepard's "Armchair Expert" podcast in 2018.
Actor Dan Stevens decided not to extend his contract after his first three years, and thus left the cast of Downtown Abbey before the third season.
After Steve mentioned in an interview that he might leave since his contract was set to expire, the network made no attempt to convince him to stay.
As an Associate Director in the Office of Public Engagement when Kal joined the Obama administration, House's authors were pressed for time to develop his character.