Hair-based Biological and Subjective Evaluation of Stress in Children

Abstract

Background : Currently, an objective measure of stress is unavailable in socially vulnerable children. In recent years, hair cortisol concentration (HCC) has attracted attention as a medium- to long-term stress assessment index. Studies have suggested that HCC is associated with low socioeconomic status and a difficult nurturing environment and may provide useful information regarding stress-related health issues in children. Additionally, estimation of other indicators, such as the dehydroepiandrosterone (DHEA) concentration, which reduces cortisol concentration and shows antistress effects, as well as the DHEA/cortisol ratio used as a resilience indicator, have attracted widespread attention and are shown to be negatively correlated with stressful life events and their perceptions. In this study, we measured concentrations of hormones in children’s hair to investigate gender-based and developmental differences and also to confirm the association between biological and subjective indices.

Methods : This study included 58 children (9-15 years) in the prepubertal to adolescent age groups. We measured HCC and DHEA (an antistress indicator) concentrations and the DHEA/HCC ratio (a resilience indicator) as biological indicators. We used the Public Health Research Center’s version of the Stress Inventory (PSI) as a subjective indicator of the correlation between biological indicators and factors associated with the stress response, stressors, and social support.

Results : We observed a moderate correlation between HCC and DHEA concentrations. HCC concentrations increased with age, and the DHEA concentration and DHEA/HCC ratio were lower in middle school students. Overall, we observed a weak association between biological and subjective indices. However, we observed significant gender-based differences in the aforementioned associations ; boys showed a moderate-to-high positive correlation between DHEA, DHEA/HCC and subjective stress, with no such association observed in girls.

Conclusions : The significant correlation between HCC and DHEA suggests the importance of DHEA as a stress hormone. Analysis of developmental differences based on hormone concentrations in hair highlights the role of hair as a bioindicator of some aspects of psychological issues in children and adolescents and may contribute to a better understanding of stress in children. DHEA concentrations and the DHEA/HCC ratio were significantly correlated with subjective stress in boys, which suggests the significance of focusing on DHEA in addition to HCC in this population. We observed no correlation between biological and subjective indices in girls, which emphasizes the need for future investigation using other psychological indicators. Considering the small sample size of this study, further large-scale research with subjects spanning a wider age range is warranted in addition to establishment of standard values for each developmental stage.