'I lost my mind': Aussie boxer's incredible confession

Koen Mazoudier was once so unwell he was locked in a jail-like mental health facility and treated like a schizophrenic.

This week he will return to the ring hoping to one day become a world boxing champion. And that is possible.

Mazoudier tells quite the tale of inspiration and overcoming adversity after a life-and-death struggle with drug addition.

"I've lost my mind and been in psychotic episodes and manic states up until the point where I was put into a mental health facility for violent and mentally ill people," the 30-year-old told AAP in the rawest of interviews.

"I was pretty much schizophrenic, like I was having full-blown hallucinations and, forget about my boxing career, it was like whether or not I was ever going to be a sane human being."

Mazoudier's first episode came in his late teens, but his most recent was this year, not even 18 months after taking Nikita Tszyu to the darkest place of his own career in an epic Australasian super-welterweight showdown in Sydney.

Mazoudier's battles began when the then-amateur star spiralled into depression after missing his last chance to represent Australia at an Olympic Games.

"I was using a lot of different drugs, like mainly psychedelic drugs and weed and marijuana, all different party drugs," he said.

"It was a steady decline of having failures in the sport, trying to then find some joy outside the sport: drinking, drugging.

"I'd have another bigger loss and find an outlet, and then you're really strict obviously doing everything right when you're getting ready for a fight."

The lowest of lows was being placed in a mental health facility and threatened with a straitjacket.

"I was originally arrested from my house and taken to hospital," Mazoudier said.

"I said I don't want to take any drugs, like don't give me anything, and they said, 'Either you take these pills or we're going to hold you down and inject them', so it was right on that borderline.

"I was on medicine they give to schizophrenic people, so I was in that sort of state, and in there it was pretty much jail for mentally ill people.