Bodyguard told the fictional story of David Budd, played by Madden, a heroic but volatile war veteran now working as a Specialist Protection Officer for the Royalty and Specialist Protection Branch (RaSP) of London’s Metropolitan Police Service.
The intense series won universal praise, numerous awards and big viewing figures when it aired last year.
But filming left Madden questioning his career choice.
“It really took it out of me. I didn’t get to see my friends, my family, do anything. It’s a relentless job, it’s an unhappy place," he said. “At the end of filming I had just gone, ‘What am I doing this for? I’m supposed to be doing the thing I love.’
"I had to take a break for a couple of months and get myself back."
In an interview with The Sun newspaper, Madden said: “And after I did get myself back a bit in my head, then you’re like, ‘OK.’
“Then seeing the rough cuts coming through of it, I was like, ‘This is something I’m really proud of actually.’”
You can purchase the full series of Bodyguard now on DVD here.
When protection officer David Budd is assigned to protect the ambitious and powerful Home Secretary Julia Montague (Keeley Hawes), Budd finds himself torn between his duty and his beliefs. Responsible for her safety, could he become her biggest threat?
The finale episode of the series last year was watched by an audience of 17.1 million people, 28-day 4-screen consolidated figures revealed.
The BBC said it was the UK’s most watched episode of any drama series across all channels since current records began, in 2002.
Plus, it was the largest TV audience outside of sporting and national events since 2010.
Bodyguard was written by Jed Mercurio and the first series also starred Gina McKee, Sophie Rundle, Pippa Haywood, Stuart Bowman, Vincent Franklin, Ash Tandon, and Nina Toussaint-White.
A second series has been rumored but not yet officially confirmed.