A psychologist says it is all too common that people come into his practice with undiagnosed brain injuries.

Michael Hempseed says about half the people who think they have treatment resistant depression, actually have a brain injury that has not been picked up by other health professionals.

While there has been far greater awareness about depression over the past 20 years, he says more is needed around brain injuries.

Lara Courtenay was a general practitioner before she suffered a head injury in 2021.

"I guess it's a bit embarrassing, I was really busy... and I was texting and walking and semi-ran into a tree on my way to work."

She did not think too much of it at the time, as she had not lost consciousness or vomited.

But she did notice lapses in memory, difficulty looking at screens and tiredness.  

"Everything was kind of numbed a bit, my senses were a bit numbed. I couldn't cope with bright lights and I couldn't be in noisy environments. I just wanted to sleep and put a pillow on my head."

After a couple months Lara's GP friends convinced her to see a concussion specialist, but she said she felt shame over the injury, especially since her struggle was not always obvious to other people.

"I think there's a lot of people in society struggling with this that aren't talking about it, a lot. And it's sad, because I think it's damaging people."

If she had not been a GP with knowledge of head injuries, she says she would've felt like she was going crazy.

"I feel grateful in a way that I knew what I knew, but it was still really hard. If you didn't know what was going on and you weren't getting the right treatment, you're not going to really get better."

Michael Hempseed, a psychologist who runs Frontiers of Hope, says that's a reality for many suffering with head injuries who have not been correctly diagnosed.

"A lot of people come to us with what they think is treatment resistant depression, so maybe they've tried medication, maybe they've tried therapy and they've found their depression doesn't seem to get any better."

About half of these people turn out to have a had a head injury that they never knew about, he says.

This lines up with ACC statistics which show nearly 40 per cent of the 35,000 people estimated to suffer a traumatic brain injury each year are not getting it checked by a health provider.

Stats from Brain Injury Outcomes New Zealand show nearly half of all of adults who have a traumatic brain injury experience persistent symptoms, meaning it was still affecting them a year or more later.  

For many of these people it's actually a relief when they are diagnosed, Hempseed says.

"They finally have an answer, they finally know what could be going on and there's a lot more understanding."

High rates in prison population

Toni Foster is a community educator at Headway, a support network for people with brain injuries.

She has been looking into research on the link between head injuries and the prison population.

A 2019 study which screened South Auckland prisoners found alarmingly high rates of brain Injuries.

"Sixty-four percent had sustained at least one traumatic brain injury in their lifetime, and 32 per cent had a history of multiple injuries."

This did not necessarily mean head injuries lead to people being imprisoned, but rather Foster said rates of alcohol or drug dependency and antisocial behaviour were high in both groups.  

But head injuries could have a negative impact on people's experience in prison, and their chances of getting out for good behaviour, she said.

"They're probably seen as difficult prisoners. They probably cope less with the stimulation that's around them, the noise the lighting and things like that. So they probably get into more struggles in the prison... and it puts them at more risk of another injury."

The Department of Corrections acknowledged that traumatic brain injuries caused a range of cognitive and emotional difficulties for prisoners and said it works with ACC to support those affected.

If someone suffers a head injury while in prison, it said inmates were able to access the same health support as they would in the community.

'Like hitting a blank wall': Struggle for long term support.

Kevin Alexander says for his head injury, another issue had been getting long term support.

While ACC did a good job of treating people whose injuries resolved quickly, he says for those with long term issues the process is difficult to navigate.

"When you don't fit inside the box, then they go, 'well we're finishing that', no explanation, no clarification, no rhyme or reason, it's just like hitting a blank wall."

ACC deputy chief executive of Service Delivery, Amanda Malu, says it has funded a number of supports and assessments for Alexander, without a significant improvement in his symptoms.

She says his recovery has not been straightforward, and she understans how frustrating that would be.

Malu says each head injury is different and ACC and concussion services adapt to each patient's needs.

The concussion service aims to prevent long term consequences of head injuries by identifying clients at risk and providing them with interventions and education, she says.

-Luka Forman/RNZ.