Saliva test may help identify boys at risk for severe depression

Saliva tests could help detect signs of depression in teenagers, particularly in boys, a recent study by researchers from the University of Cambridge reveals.

One in every six people suffers from some form of depression, with symptoms in most cases appearing before the age of 24, according to the researchers. However, there is no definite biological test to detect the condition.

The new study could signal a change in this, the researchers said, explaining that the saliva test may be an effective screening tool in detecting symptoms of severe depression

"This is the emergence of a new way of looking at mental illness," said Joe Herbert, one of the study's authors, said in a press release. "You don't have to rely simply on what the patient tells you, but what you can measure inside the patient."

The researchers measured the cortisol levels of more than 18,000 teenagers, aged between 12 and 19, using their saliva. The younger participants were also asked questions in order to identify signs of mild depression.

As the researchers followed up with the participants over the next three years, they found that the boys with both higher cortisol levels and symptoms of mild depression were 14 times more likely to suffer from severe depression later on.

"This finding starts to link the less understood factors and the actual onset of depression," Dr. Simon Crisp, a Melbourne clinical psychologist, told the Herald Sun.

Girls identified with higher levels of cortisol, on the other hand, were only four times more likely to develop severe depression later on.

According to the health experts, the gender specific hormones, like androgen for males and estrogen and progesterone for females, might be the reason girls react differently compared to boys.

"All hormones, including sexual hormones, influence brain function and behavior," Dr. Carmine Pariante, a professor of biological psychiatry at the Institute of Psychiatry at King's College London, told The Associated Press.