New research, conducted by scientists at James Cook University and published in the medical journal Scientific Reports, found that a small group of young Indigenous people had an adverse biological reaction to stress, and that an important morning release of the stress hormone, cortisol, was missing in the participants it tested.
A release of cortisol at the beginning of the day helps the body prepare for dealing with the daily hassles and stresses of life. The absence of this hormone in the morning, therefore, can be a setback.
It’s a phenomenon common in people who experience severe mental illnesses, including depression and psychotic disorders.
"It allows us to objectively monitor efficacy of programs and policies to reduce the Indigenous health gap."
For the young people studied, it is not definitively known why there is a lack of cortisol production, but trans-generational trauma could play a part.
Professor Zoltan Sarnyai, who led the research, says that doesn’t mean the finding in young Indigenous people, all of whom attend James Cook University, is due to genetics.
“Because the way we interviewed participants in our study was asking them if they considered themselves Indigenous,” he said.
“Similarly our controlled non-Indigenous group was comprised of individuals who defined themselves as non-Indigenous, and they came from racially diverse backgrounds.”
“So our findings are unlikely to be due to any sort of ‘Indigenous gene,’ it is more likely to do with the Indigenous experience,” he said.
That experience is often characterised by poverty and racism – and linked to trans-generational trauma. Something researchers believe could prove a link between hormone abnormality and trans-generational trauma, called epigenetics.
Epigenetic changes occur when genes are activated and de-activated, potentially as a result of early experiences or psychological trauma, without changing the DNA code.
Closing the health gap
It's hoped the study will open up ways to predict the development of mental health issues in the Indigenous community.
"It allows us to objectively monitor efficacy of programs and policies to reduce the Indigenous health gap," Prof Sarnyai said.
That efficacy, for instance, could be the measurement of a person’s biological stress response, before and after mental health programs are implemented.
While the creation of data relating to biological stress could, in turn, inform policy.
Professor Sarnyai is currently discussing with Indigenous health organisations ways that this research can be implemented.
But he admits more research needs to be done, saying their small study group isn’t representative of the wider Indigenous experience.
“To do anything bigger than that would obviously require more funding.”