New treatments for depression and Huntington’s disease could be developed after Melbourne scientists discovered a way to correct abnormal stress hormone levels.
Huntington’s disease was previously thought to be solely a degenerative condition of the brain but scientists from the Florey Neuroscience Institutes have found it can also affect the adrenal glands.
Adrenal glands sit on top of the kidneys and are responsible for releasing the stress hormone cortisol through messages received from the hypothalamus and pituitary glands in the brain.
Severe depression, which can be affected by stress, is one of the common symptoms of Huntington’s disease, along with dementia and movement disorders.
The new research found that mice with Huntington’s had severe adrenal dysfunction which led to a prolonged release of cortisol, especially in females.
But when the mice were exposed to brain stimulation, this corrected the adrenal glands’ cortisol secretion, study leader Associate Professor Anthony Hannan said.
When the adrenal gland cells were extracted and observed in the lab, those from mice exposed to the extra stimulation still remembered’ to correct the abnormality and did not secrete too much cortisol.
This means that cognitive stimulation is not just good for the brain, but also the adrenal gland.
‘This idea that this enhanced cognitive stimulation is good for the adrenal gland is quite extraordinary,’ Assoc Prof Hannan told AAP.
Assoc Prof Hannan said the findings could help scientists develop new therapies for Huntington’s disease.
‘We can’t just be targeting those brain cells, we have to be thinking about some of these areas outside the brain, such as the adrenal gland, may need to be treated as well.’
He said the findings could also be relevant for depressive disorders and other brain conditions affected by stress, such as Alzheimer’s disease, dementia, schizophrenia and bipolar disorder.
Assoc Prof Hannan said the right combination of a future drug, plus exercise and cognitive stimulation, could be the most therapeutic mix for Huntington’s sufferers but trials in humans would need to be done.
Previous studies by Florey Neuroscience Institutes scientists have shown that depression in Huntington’s patients is not just a reaction to the diagnosis, but is in fact biologically linked to the disease.
Because the hypothalamus is in the brain, controlling cortisol release, psychological stress can have a direct biological impact on the body via the adrenal gland, Assoc Prof Hannan said.
There are cortisol receptors around the body therefore high levels of the stress hormone can impact the brain and other organs.