text_1: Cortisol levels in children's hair may reveal future mental health risk
text_2: This story reports that in an Australian study of 70 children (average age 9.5 years), those who had experienced a higher number of traumatic events also had higher levels of the stress hormone cortisol in samples of their hair. The researchers are hypothesizing that the cortisol levels might be a marker of future mental health problems in the children, as people with depression and other mental health problems, as well as physical problems like diabetes, sometimes have high levels of cortisol. Here’s the problem with this story: The study being reported on never actually looked at whether cortisol levels had anything to do with future mental health diagnoses. And in fact, cortisol levels were found not to be correlated with current depressive symptoms in these children. Moreover, the study had such a small sample as to make any conclusions resulting from it highly uncertain. So it’s a huge stretch to claim that cortisol in hair “may reveal future mental health risk” in children. We wish the story had been more cautious, especially in its headline, when discussing the implications of this very preliminary research. Childhood lays the foundation for one’s health over a lifetime, so identifying people who have risk factors for health problems early on — as with a simple hair test — is an attractive idea. This might allow for early intervention to modify risk and get people into treatment sooner, lessening the impact of disease or behavioral problems on their lives.