Scientists could lower the rate of depression in
people over 70 years old by reducing the amount of
the amino acid in their blood stream.
Image: iStockphoto

In a discovery that may help reduce the burden of depression in later life, West Australian researchers have found a new link between the condition and the amino acid homocysteine.

The research by a team at the Western Australian Centre for Health and Ageing (WACHA), based at the Western Australian Institute for Medical Research (WAIMR), suggests, for the first time, that high levels of homocysteine contributed to an increased risk of depression in people over 70 years old.

The results from the Health in Men Study, involving more than 3,700 men aged over 70, were published in the November issue of the Archives of General Psychiatry, the world's leading psychiatric journal.

"Previous studies revealed that older adults with depression have high concentrations of homocysteine, but nobody was sure whether it actually contributed to cause older people to become depressed," WACHA Director of Research and University of Western Australia Professor Osvaldo Almeida said.

"We've now found that the MTHFR gene, which we knew contributed to increasing the basal concentration of homocysteine by 20 per cent, also increases the risk of depression by about 20 percent in older people."

"These results suggest that if we are able to reduce the plasma concentration of homocysteine by one fifth, we can reduce the number of elderly Australians who are affected by depression by the same amount."

Around one million Australian adults live with depression each year and is extremely prevalent among older age groups, with as many as 51 per cent of high aged care residents reported as depressed.*

Professor Almeida said the research was an important step forward in understanding what led to the development of depression in later life and how to create effective prevention strategies.

"Whilst this study was done in men, the findings are applicable to women and, given that we already know how to reduce the amount of circulating homocysteine in the plasma, this research may have enormous implications on how we treat and prevent depression worldwide," he said.

"Depression is more than just a low mood - it's a serious illness and can have serious effects on physical and mental health so this research is very important."

WAIMR Director Professor Peter Klinken praised Professor Almeida's team and said the trial was a great example of how medical research could have a positive effect in the community.