Can Stress in Hair Reveal Children’s Mental Health Risks?

What parents around the world should know about new research on stress, chronic illness, and mental health

When we think about stress in children, we often imagine short-term worries about school, friendships, or big life changes. But what about long-term stress that quietly builds up over months or years—especially for children living with chronic physical illnesses?

A recent study from the University of Waterloo in Canada suggests that this hidden stress may leave a trace in an unexpected place: a child’s hair. By measuring cortisol, a hormone linked to stress, in hair samples, researchers found important clues about which children may be at higher risk of depression, anxiety, and behavior difficulties.

Why This Matters for Families

Children with chronic physical illnesses (such as asthma, diabetes, or epilepsy) often face daily challenges—taking medication, missing school, or needing to adapt their activities. These difficulties can take an emotional toll, increasing the risk of mental health struggles.

In fact, studies estimate that around 40% of children with chronic illnesses experience mental health problems—a much higher rate than their healthy peers. Left unrecognized, these challenges may affect school performance, relationships, and long-term well-being.

The new research gives hope that doctors and families could detect these risks earlier, using a simple and non-invasive method.

What the Study Found

• The research followed 244 children with chronic illnesses for four years.

• Cortisol levels were measured from hair, which reflects long-term stress exposure.

• More than two-thirds of the children showed persistently high stress levels.

• These children were more likely to struggle with anxiety, depression, or behavioral difficulties.

• Children whose cortisol levels went down over time showed fewer emotional and behavioral problems.

In other words, children whose bodies were “stuck” in a high-stress state faced greater mental health risks.

A New Tool for Early Support

This approach could help doctors and psychologists spot children at risk before serious problems develop. Early identification means families could receive more targeted support—whether that’s therapy, counseling, stress-management strategies, or family-based interventions.

As Dr. Mark Ferro, one of the study’s authors, explains: “Hair cortisol offers a non-invasive, easy-to-collect biomarker that could one day be used to screen children and track whether treatments or support programs are helping to reduce stress.”

What This Means for Parents Worldwide

While this research comes from Canada, its implications are global. Parents everywhere can take away three key messages:

1. Chronic illness affects more than the body – Emotional health and stress need just as much attention as physical care.

2. Stress can accumulate silently – Even if a child doesn’t always show it, long-term stress may affect their mood and behavior.

3. Early intervention matters – The sooner mental health risks are identified, the better the outcomes for children and families.

   
   

How Parents Can Help

Even without access to hair cortisol testing (which is still in the research stage), parents can:

• Talk regularly with their child about feelings, not just symptoms.

• Watch for changes in sleep, appetite, school performance, or social behavior.

• Seek professional support early if concerns arise. Pediatricians and psychologists can guide families toward appropriate care.

• Advocate for integrated care – asking doctors to consider both physical and emotional well-being in every check-up.

Final Thoughts

At Baumgarten Child Psychology and More, we believe that children’s mental health deserves the same priority as their physical health. This study shows just how connected the two are—and how science is finding innovative ways to give families the tools they need to protect their children’s well-being.

Stress may leave its mark in hair, but with early support, children living with chronic illness can still thrive, emotionally and physically.