Warren McKinlay was slowly starving himself to death because he could see no point eating as he was not ‘alive’.
Instead the 35-year-old lived in a bizarre “alternate reality” which left him feeling like a “ghost”.
Incredibly he was cured after meeting another British soldier suffering from the billion-to-one Cotard’s Syndrome.
The pair helped each other to recover while being treated at the Headley Court rehabilitation centre.
There have been just a handful of recorded cases of the condition since it was first recognised in the 17th Century.
Unlucky sufferers genuinely believe they are deceased or that parts of their body no longer exist.
Some even die from starvation because Cotard’s Syndrome makes them they feel they no longer have to eat.
Warren, from Braintree, Essex, said: “I convinced myself I was actually dead. I felt I was literally a dead man walking. It was as if I was a ghost.
“I was treated at a time when many soldiers were coming back from Afghanistan with no legs and no arms.
“I was surrounded by stories of death – it was like I was in a living nightmare. I refused to eat as I thought there was no point as I’d already died. It was like I was living in an alternate reality.
“I’d hear my dad calling my name just like he was in the room with me but there was no way it was him as he was living miles away.”
Warren’s symptoms began after he ended up at Headley Court in 2005 following a serious motorbike accident.
He had spent seven years in the Royal Electrical and Mechanical Engineers and served in Bosnia.
His horror accident left him fighting for his life with a broken pelvis and back and two ruptured lungs.
He managed to pull through and was able to be with wife Sarah for the birth of their daughter Katie four months later.
But Warren’s family began to notice he was acting strangely and seemed distant when they tried to get close to him.
“I wasn’t myself at all and couldn’t understand it – every time there was a loud noise or Katie would cry I flew into a rage,” he said.
“I loved her from the moment she was born, but I would have to leave the house as the noise was like a searing pain in my head.
“I knew something desperately wasn’t right but I had no idea what it was, as I’d never been like that before the accident.
“I was in a wheelchair for for months after the accident and I’d wheel myself from one room to another and forget what I’d gone in there for.
“I had a total blank of the six weeks following the accident.
“One day I drove to the shops and got a taxi home. It was only when I saw my car wasn’t outside the house that I’d realised what I’d done.
“I was scared at what was happening to me. I’d also lose words in the middle of sentences and just couldn’t get them out.”
Warren was eventually referred to Headley Court in Surrey after falling victim to Cotard’s Syndrome.
He started to believe he was a “dead man walking” as he spent all day surrounded by injured soldiers.
Warren said: “By the time I got there for some time I’d become convinced I was actually dead.
“I know it sounds utterly bizarre, but I genuinely believed I’d died in the crash, but for some reason my spirit hadn’t moved on.
“I was convinced that I didn’t have to eat, because I was dead I had no need for food any more. I’d sit for hours in a room refusing to talk to anyone.
“I’d gone completely into a shell, Sarah was loving and tried everything to help me, but I felt I couldn’t share what was happening to me.
“Within days they told me I had a serious brain injury. Until that point I had no idea.
“Then, when I confided in my therapist that I thought I’d died, I finally got a diagnosis of Cotard Syndrome”.
Cotard’s - named after French neurologist Jules Cotard in 1880 - is a form of delusional psychosis.
This distorted reality is caused by a malfunction in an area of the brain which recognises faces and processes emotions.
“At first it was a real shock,” Warren said. “I refused to believe it and I insisted there was nothing wrong with me.
“I couldn’t process the fact I had a brain injury, which I now know is actually a symptom of having a brain injury.”
By a freak coincidence Warren made friends with another Cotard’s sufferer at the rehab clinic.
“He also experienced the same thing, in billion to one odds, as there’s been so few people diagnosed with this through the years,” he said.
“He came to the conclusion that he was such a different person that the old him was dead, so he started again with a new identity.
“I never thought about doing that, but talking through it and seeing how he came to terms with it helped me with what I’d gone through.
“With the help of therapists I was able to move on and live again.
“The odds that two of us had such a rare condition were like winning the lottery – but Headley Court is a place where exceptional things happen.
“Whilst I no longer believe I died in my accident, I still struggle with the daily challenges of living with a brain injury.
“I still find it hard to cope with loud noises and crowded places, but I no longer shy away from them.
“I push myself to face these challenges head on, because if I don’t, my brain injury wins.
“I’ve lost the person I was before the accident and I’m someone different now.
“It was an utterly bizarre thing to experience, but I see it as a part of my recovery and in the past now.”
Wife Sarah, 35, said: “It’s hard to comprehend, even for me, what Warren has gone through, but finally our lives are back on track.
“We still both live with brain injury, but Warren has achieved so much I’m incredibly proud of him.”
In April Warren, who also has a four-year-old son Frazer, joined Team BRIT - an endurance racing team made up of injured veterans.
“Team Brit has given me a renewed focus in my life, as my injuries mean I will struggle to work again,” he said.
“We race all over the country and Europe, in specially adapted hand control karts and it’s given me my direction back.
“No matter how bad things are, there’s always a reason to live - I’ve learned that from the soldiers I recovered with.”