Elevated hair cortisol concentrations in trauma-exposed adolescents who engage in nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) is common in trauma-exposed adolescents and has been linked to dysregulation of stress-response systems, including the hypothalamic-pituitary-adrenal (HPA) axis. Most existing evidence is based on short-term cortisol measures, whereas hair cortisol concentrations index cumulative HPA axis activity over several months. We therefore investigated hair cortisol concentrations in trauma-exposed adolescents by comparing those with and without recent NSSI.

Fifty trauma-exposed adolescents (mean age = 16.02 years; 68% identified as female, 26% as male, and 6% as gender-diverse; 72% were assigned female at birth and 28% male at birth) were recruited. Recent NSSI within the past three months and trauma symptom severity were assessed using clinical interviews. Proximal 3-cm hair segments were analyzed to index cumulative cortisol secretion over the corresponding three-month period. Group differences in hair cortisol concentrations were examined using t-tests on log-transformed values, with additional analyses adjusting for dimensional trauma symptom severity.

Trauma-exposed adolescents with recent NSSI (n = 23) showed higher hair cortisol concentrations than those without NSSI (n = 27; p = .006, Hedges' g = 0.86). These group differences remained significant after adjusting for trauma symptom severity, which was not significantly associated with hair cortisol concentrations.

In trauma-exposed adolescents, recent NSSI was associated with elevated cumulative HPA axis activity, indexed by higher hair cortisol concentrations. This finding highlights the relevance of long-term stress-system functioning in adolescents who engage in NSSI and underscores the importance of considering cumulative, rather than solely acute, indices of HPA axis activity in clinical research.