AC/DC frontman Brian Johnson has recalled the pain of realising that Malcolm Young wasn’t going to recover from dementia.

The Aussie giants’ mainman was forced to retire before work began on 17th album Rock Or Bust. Brother Angus recently reported that, although Malcolm is credited as a co-writer, he hasn’t heard the record.

Speaking at a promotional event for the Alzheimer’s Association’s Highway To Help initiative, Johnson tells NC9: “Malcolm was the man who started the band. He was our spiritual leader. He was our Spitfire.

“I guess we’re like everyone else with loved ones who have this condition. It was that desire to fix something that’s unfixable.

“You just expect that they’re going to get better. You think there’s going to be a pill that’s going to fix them. You think there’s going to be a miracle – and of course, one day you wake up and realise there isn’t, and it hurts.”

But Highway To Help co-founder Dr Justin Boyd offers a positive message, saying: “We’re very close in curing this disease. We’re further than the mainstream acknowledges. We keep reading clinical trial after clinical trial fails; but the failures of today represent the research of 10 years ago.”

Meanwhile, Angus says the way Malcolm led the band through the death of frontman Bon Scott in 1980 offered moral support in dealing with the mainman’s departure.

He tells Aftonbladet: “When Bon died, Malcolm got me through all of that. He said, ‘The two of us will sit and just keep working.’ It was the best therapy for us; we didn’t know, ‘Do we continue or not?’ We could do that, and then we could decide later what we wanted to do. So it took a lot of pressure and a lot of mourning away.”

Rock Or Bust is released on Monday and it’s available for streaming in full in the US. The album received its official launch in the small Australian town of Rock at the weekend. AC/DC will tour next year with Stevie Young in Malcolm’s place – but the status of drummer Phil Rudd remains in doubt after his arrest over threatening to kill.