Holby City is shining the spotlight on the complex issue of mental illness as consultant Sacha Levy battles his demons next week. Here, Bob Barrett - who plays the medic - reveals why Sacha is driven to the edge...

Bob Barrett talks Sacha’s dramatic day in Holby City…

Since his depression diagnosis, Sacha’s had a lot of turmoil in his life hasn’t he?

Bob Barrett: “He hasn’t had an easy ride. It all started with his break-up with Essie, which I think he found incredibly hard to deal with. There was an episode a few weeks ago, which explored Sacha’s worst day, where just about everything went wrong for him. All the things Sacha clings onto are family, work and love – but he’d lost touch with his family, his research project fell apart at work and his relationship with Essie didn’t work out, so he’s been struggle with the accumulation of all those things.”

And, obviously, another big even in Sacha’s life was Jac getting shot… the pair have always been so close haven’t they?

BB: “Yes. Jac and Essie are the two people in the hospital Sacha is closest to, so nearly losing Jac and nearly losing Essie [to cancer] was almost unbearable for him really. Sacha’s always been able to help people but when he knew he couldn’t help Jac or fix Essie’s cancer, he started to feel impotent.”

Sacha after operating on Connor in Holby City

Is that why, in next week’s Holby City, Sacha takes patient Connor Barrat’s death so badly?

BB: “Yes, the straw that breaks the camel’s back for Sacha is this patient. Sacha thinks: ‘If I can fix Connor and keep him alive all will be well.’ So when he loses Connor, he loses all hope!”

Devastated by Connor’s death, Sacha heads up onto the hospital roof, where Ric finds him – but he’s not exactly supportive is he?

BB: “Not exactly! Ric really doesn’t know what’s wrong with Sacha because Sacha’s been so good at hiding that he’s suffering from depression. He’s dependable Sacha – he likes being the first person people go to with their problems but he won’t ever admit he’s got one of his own. So when he does open up to Ric, Ric tells Sacha to ‘man up’ and they end up arguing. Sacha starts to think everything is his fault and that he won’t be missed, which sends him down a spiral of despair…”

Holby City Sacha talks to Ric

After visiting Connor in the mortuary, Sacha is overwhelmed and breaks down in the staff locker room! Were those scenes emotional to film?

BB: “There were big, emotional, draining days involved in filming this episode but, as always with these things, the camaraderie on set was amazing. So, yes, there’s emotional stuff but I don’t find that too difficult because I’m quite an emotional chap anyway! Weirdly, though, it didn’t affect me while we were filming – but I had a week off afterwards and that’s when it hit me!”

Sacha talks to Dom

Sacha then pays separate visits to Dom (pictured), Jac and Essie and it’s almost like he’s saying his ‘goodbyes’ to them. Is this a sign that he’s going to do something drastic?

BB: “In his way, he IS saying goodbye to the people who mean the most to him. Sacha immediately goes up onto the roof and heads straight to the edge. There seems to be absolutely no question in his mind that he’s going to jump – he really doesn’t expect anyone to stop him…”

Why do you think it’s important for a show like Holby City to raise awareness of mental health issues and suicide?

BB: “Depression is the ‘silent’ disease, people won’t talk about it because there’s still a stigma attached. And men in particular are notoriously bad at talking about it. Also, it’s especially frowned upon for a doctor to talk about suffering from depression because their job is to care for other people. So it’s a really important story to tell.”

Watch Sacha’s crisis unfold on Holby City on Tuesday August 28 at 8pm on BBC1.