Depression, sad
Researchers have identified the first biomarker associated with major depression.Liz Grace/Flickr

Researchers have identified the first biomarker associated with major depression.

Depression is the outcome of chemical changes in the brain, caused by stress or hormonal changes. It is crucial to detect and treat the problem early, as delayed treatment worsens the situation and will lead to self-destructive behaviour and even suicide. Now this ground-breaking discovery is expected to improve the way the mental disease is being diagnosed and treated till date, particularly in boys.

In the study, adolescent boys, who displayed depressive symptoms along with a spike in stress hormone cortisol, had 14 times higher risk of developing clinical depression than others.

"This new biomarker suggests that we may be able to offer a more personalised approach to tackling boys at risk for depression. This could be a much needed way of reducing the number of people suffering from depression, and in particular stemming a risk at a time when there has been an increasing rate of suicide amongst teenage boys and young men," first author of the study, Dr Matthew Owens from the University of Cambridge, said in a news release.

For drawing a conclusion, researchers looked at two groups of teenagers, consisting 660 and 1,198 members respectively. The first group got tested their morning cortisol levels four times a week, during school days and repeated the test nearly one year later. The second group tested their morning cortisol levels during three school days. Researchers monitored the youngsters and analysed prevalence of depressive symptoms among them during the same period. Based on the severity of depressive symptoms self-reported by the youngsters and cortisol levels, researchers divided both the groups into four.

Of the total, nearly 1,858 teenagers with high depressive symptoms and elevated cortisol levels were identified to be at a higher risk of developing clinical depression than the teenagers who had normal cortisol levels and low symptoms of depression. To confirm the link, participants again underwent certain memory tests. Teenagers in the high risk group fared worse on tests and could not provide a detailed account of certain events in their life, including their picnic experience. This occurrence was mainly because high levels of cortisol suppress autobiographical memory recall, the researchers said.

The study has been reported in Proceedings of the National Academy of Sciences.