"Normally, people had this sort of injury if they were in a coma or if they were declared dead."

That is what Alex Walker was told when she woke up in Sydney's Royal Prince Alfred (RPA) Hospital.

Key points: Alex Walker entered the world of long-term rehabilitation after a motorbike crash

Alex Walker entered the world of long-term rehabilitation after a motorbike crash After her physical injuries improved, the mental injuries remained

After her physical injuries improved, the mental injuries remained She has now entered a program that has given her "hope"

Ms Walker was riding her motorbike in December when a rope she was carrying came loose and got caught in the chain, causing her to crash.

"I was declared nearly brain-dead on the scene and taken to the RPA where they put me in an induced coma," Ms Walker said.

"I broke my back, my pelvis, four ribs and then had significant nerve damage to my right arm — I couldn't move my arm when I woke up."

Despite being lucky to be alive, as an artist and a social worker, the news that she would not be able to use her injured right arm — as well as having to learn how to walk again — was hard to take.

She was thrown into the world of long-term rehab.

The scars left on Alex Walker's body after the motorcycle crash. ( Supplied )

But once her physical recovery progressed, another kind of injury emerged — an injury her brother Sean described as "invisible".

"The physical injuries had subsided [but] she was still left in this really dark place," he told the ABC.

"That was when we realised something wasn't right. The invisible injury, the brain injury, hadn't been addressed fully and there was this whole new space that needed to be entered.

"It was really, really hard."

Alex Walker and her twin brother Sean ( ABC News: Kathleen Calderwood )

Ms Walker said the brain injury meant she had trouble sleeping and processing information.

"I was getting really overwhelmed," she said.

"If something stressful came into the picture, I wasn't able to emotionally regulate very well.

"It was an extreme amount of distress and anxiety and this incredible low, the deepest depression I've ever felt in my life."

After months of discomfort, Ms Walker was referred to Jodi Cartoon, a doctor involved in Australia's first fellowship in brain injury psychiatry at the University of Sydney's Brain and Mind Centre.

"It's merged together two fields that are already inextricably linked," Dr Cartoon said.

"We know that there's just so much overlap between the brain injury and psychiatry side."

Ms Walker said after feeling lost in the health system, that all turned around when she started seeing Dr Cartoon.

Alex Walker painting post-accident ( ABC News: Kathleen Calderwood )

"Once someone explained that [my] brain had been damaged and that I was experiencing depression and anxiety because [of it], I felt so much relief," she said.

Now four more psychiatrists will receive the highly specialised training through a $2 million investment from NSW Government insurer iCare.

"Seventy per cent of iCare's lifetime care customers have a brain injury and out of those, 50 per cent also have a mental health condition," iCare customer and community chief Sara Kahlau said.

"So there's a large number of people that we're trying to reach through this program."

Ms Walker is yet to return to work, but she has started painting again — with both arms — and is feeling positive about her recovery.

"I had hit the point where I was so unwell that I didn't see a future for myself," she said

"I would say I was suicidal … so I don't know where I would be [without Dr Cartoon] to be honest.

"I'm feeling like there's hope in the future, I'm going off and doing courses and being gentle with myself, and waking up and feeling happy again."