Series two of the gripping ITV drama Malpractice takes viewers back into the chaos of an underfunded, understaffed NHS hospital, where doctors and nurses working under extreme pressure must make instant life-or-death decisions.

Second time around, psychiatric registrar James Ford (Tom Hughes, Prince Albert in Victoria) has to choose between seeing a struggling postnatal mother and sectioning a psychotic patient. The Medical Investigations Unit’s Norma Callahan (Helen Behan) and George Adjei (Jordan Kouamé) return from series one to explore the fallout from Ford’s actions.

The first episode of series two of Malpractice received a sold-out premiere in Leicester Square, followed by a Q&A with Hughes, Behan, World Productions executive producer Emma Luffingham and the show’s creator and writer, Grace Ofori-Attah.

Series one was set in A&E, but this time Ofori-Attah bases the drama in a world she knows inside out – the former NHS doctor was a consultant in addiction psychiatry before turning to full-time writing.

While public awareness of moderate mental illness has increased, severe illness is still “heavily stigmatised”, said Ofori-Attah. “It’s very difficult for people to understand what it means to be suffering from an enduring, chronic mental illness. It escalates quickly and can be frightening for everyone involved – it’s something that needs to be talked about more openly.”

Even in hospitals, she added with feeling, mental health is undervalued: “There is an unspoken hierarchy and psychiatry is right at the bottom.”

Behan was a nurse before turning to acting and making her TV debut – as a nurse – in Shane Meadows’ This Is England ’88. “I tend to look at medical shows and poke holes, going: ‘That’s wrong, that’s not how they do that.’ [Grace’s writing] is so authentic; it really felt like it was an honest betrayal, warts and all.”

Recalling her nursing days, Behan said: “You remember your first death... and afterwards you’re told, ‘Dry your eyes, get a cup of tea, then get back out there, strip that bed.’ It’s a cycle. Nurses, medical staff and doctors have their own mental problems from the job because you’ve got this unending layer of trauma that you’re supposed to just suppress."

“What this show does exceptionally well is bring you right up [close] with people... their sweat, their trauma... These people are human beings. They’re flawed. They are, like you would be, absolutely shitting it when something bad happens."

Hughes’ experience of medicine amounts to a role in period drama Casualty 1909, but he was attracted to playing Dr Ford by “the quality of Grace’s writing, not only that every character is so multi-faceted... but also the twists within it. If it doesn’t come from the writing, it’s very hard to get a show to sing.”

Discussing his character, he said: “There’s an over-confidence to James. He’s not confined by the expectations of social norms and etiquette – he believes that people are too reserved and don’t connect with one another in the way they should. That can make him an empathetic and very good doctor, but it can also lead him to cut a few corners.”

Malpractice, which is filmed in Belfast, does two things very well, said Luffingham: “It’s authentic, and speaks to the NHS and the problems facing it, but it’s also a cat-and-mouse thriller. We didn’t want it to feel like a lecture.”

Yet the series has a sense of realism that is rare for medical dramas. For this, Ofori-Attah is quick to praise the input of the show’s medical consultants, Dr William Shanahan, Dr Sophie Relph and Dr Abigail Smith.

Malpractice triumphs as a thriller, as clearly shown by audience gasps during a harrowing scene at the premiere. But Ofori-Attah hopes it will also raise awareness of mental health issues.

“There is no health without mental health. It is so essential to a good and wholesome life. People may seem normal, but you don’t know what they’re going through or what they’ve been through.”