Background: Research suggests internalizing symptoms are characterized by blunted cortisol reactivity to psychosocial stress during preschool. However, these studies used multiple stressors, differing from adult work on reactivity and risk using one stressor. The current study seeks to validate cortisol reactivity to the Trier Social Stress Task-Child version (TSST-C) for the first time with children younger than 7 years, while also examining the role of internalizing diagnoses on cortisol reactivity.

Method: We obtained cortisol reactivity from 35 children (4–8 years old) across the TSST-C in the child's home using 8 samples (−30 m, 0 m, 15 m, 25 m, 35 m, 45 m, 55 m, 65 m). Speeches were coded for fear. Clinicians administered a validated semi-structured diagnostic interview (K-SADS) to mothers: 9 children with a diagnosis of depression/anxiety and 27 without.

Results: 67% of children exhibited cortisol responses (at least 10% increase over baseline). Repeated measures ANOVA revealed overall higher cortisol output in controls than those with anxiety/depression F(1,32) = 4.45, p = .043. Most pronounced was a blunted peak at 35 minutes post stressor F(1,39) = 5.45, p = .025. Coded fear verbalizations were related to blunted cortisol reactivity at trend level F(1,26) = 2.93, p = .10.

Conclusions: This study provides support for the TSST-C in children under 7, in the home, with multiple cortisol data points. Consistent with previous literature, results also suggest internalizing diagnoses may present as blunted cortisol reactivity in young children.