Patrick Dempsey accused of 'terrorising the set' on Grey's Anatomy before departure

Patrick Dempsey has been accused of "terrorising the set" on Grey's Anatomy before his shocking exit from the show.

In journalist Lynette Rice's new unauthorised oral history of the show, How to Save a Life: The Inside Story of Grey's Anatomy, staff on the long-running medical drama offered up insight into the alleged issues that led to Dempsey's character Derek 'McDreamy' Shepherd being killed off in season 11 in 2015.

That season, executive producer James D. Parriott was reportedly brought back onto the show to serve "as a veritable Dempsey whisperer" amid talk of the actor's diva-like behaviour and tension between him and lead actress Ellen Pompeo.

"(Showrunner/creator) Shonda (Rhimes) needed an OG to come in as sort of a showrunner for fourteen episodes," he explained. "There were HR issues. It wasn't sexual in any way. He sort of was terrorizing the set. Some cast members had all sorts of PTSD with him. He had this hold on the set where he knew he could stop production and scare people. The network and studio came down and we had sessions with them. I think he was just done with the show. He didn't like the inconvenience of coming in every day and working. He and Shonda were at each other's throats."

Dempsey didn't respond directly to Parriott's comments in the book, but admitted working 15-hour days for 10 months and not having "control over your schedule" was tough.

"Doing that for eleven years is challenging. But you have to be grateful, because you’re well compensated, so you can’t really complain because you don’t really have a right," he said.

Producer Jeannine Renshaw claimed, "A lot of the complaining... I think Shonda finally witnessed it herself, and that was the final straw. Shonda had to say to the network, 'If he doesn’t go, I go.'"

Parriott added that different scenarios for McDreamy were considered but they "ultimately decided that just bringing him back (to set after a multi-episode break) was going to be too hard on the other actors. The studio just said it was going to be more trouble than it was worth and decided to move on."

The actor didn't acknowledge his alleged behaviour in the book, but noted he was "very happy to have moved on with a different chapter in my life."

He reprised the role for a number of dream sequences during the most recent season.