If your teenage son is showing mild signs of depression, an experimental saliva test could determine if he’s at a risk for severe depression later in life.
In a study published in the journal Proceedings of the National Academies of Science, researchers examined the saliva of 1,800 teens between ages 12 and 19, and tracked the teens’ depression symptoms and mental illness diagnoses for up to three years later.
The test’s results were most pronounced for boys. Boys with mild symptoms of depression and high levels of cortisol–a stress hormone–were 14 times more likely to have a clinical depression diagnosis later on, compared with teens with lower levels of the hormone. For girls, high levels of cortisol put them at a four times greater risk for major depression later on.