Hair Cortisol and Its Association With Psychological Risk Factors for Psychiatric Disorders: A Pilot Study in Adolescent Twins

Abstract

Measuring cortisol in hair is a promising method to assess long-term alterations of the biological stress response system, and hair cortisol concentrations (HCC) may be altered in psychiatric disorders and in subjects suffering from chronic stress. However, the pattern of associations between HCC, chronic stress and mental health require clarification. Our exploratory study: (1) assessed the association between HCC and perceived stress, symptoms of depression and neuroticism, and the trait extraversion (as a control variable); and (2) made use of the twin design to estimate the genetic and environmental covariance between the variables of interest. Hair samples from 109 (74 female) subjects (age range 12-21 years, mean 15.1) including 8 monozygotic (MZ) and 21 dizygotic (DZ) twin pairs were analyzed. Perceived stress was measured with the Perceived Stress Scale and/or the Daily Life and Stressors Scale, neuroticism, and extraversion with the NEO-Five Factor Inventory or the Junior Eysenck Personality Questionnaire, and depressive symptoms with the Somatic and Psychological Health Report. We found a modest positive association between HCC and the three risk factors -perceived stress, symptoms of depression, and neuroticism (r = 0.22-0.33) -but no correlation with extraversion (-0.06). A median split revealed that the associations between HCC and risk factors were stronger (0.47-0.60) in those subjects with HCC >11.36 pg/mg. Furthermore, our results suggest that the genetic effects underlying HCC are largely shared with those that influence perceived stress, depressive symptoms, and neuroticism. These results of our proof of principle study warrant replication in a bigger sample but raise the interesting question of the direction of causation between these variables.

Hair Cortisol in Twins: Heritability and Genetic Overlap with Psychological Variables and Stress-System Genes

“…However, contrary to the results of our previous pilot study 38 , no significant phenotypic or genetic overlap was found between HCC and any of the three psychological variables. Although no study to date has investigated the association between HCC and neuroticism, the present results are consistent with a previous investigation of 125 twin pairs, which showed heritability for neuroticism and morning cortisol secretion in saliva but no phenotypic or genetic overlap between these two variables 33 .…”

“…These studies have also revealed that these risk variants show partial overlap. In a subsequent pilot study, the present authors measured HCC and the three psychological variables in a sample of 109 children and young adults, which included eight monozygotic- and 21 dizygotic twin pairs 38 . Due to the small sample size, no reliable heritability estimates for HCC could be generated.…”

Proving a negative? Methodological, statistical, and psychometric flaws in Ullmann et al. (2017) PTSD study

“…In order to assess long-lasting psychological trauma and ongoing stress (PTSD-like symptoms) among adult males subjected to genital cutting, Ullmann et al measured objective hair cortisol and cortisone levels [7,8] and administered five introspective (subjective) self-report personality-stress questionnaires (see Box 1, "Lack of psychometric sophistication" for a description) to a small sample of 20 self-selected circumcised and genitally intact men who had immigrated to Germany from the former USSR. In order to avoid "post-war psychosocial transgenerational transmission influences as well as acculturation effects" related to stress, men whose parents had been born before the end of WWII were excluded from the study.…”

Hair glucocorticoids are not a historical marker of stress – exploring the time-scale of corticosterone incorporation into hairs in a rat model

“…With powerhouse studies such as these, it is easy to understand the method's popularity. Adoption of hGC analyses has happened with great speed across several disciplines: whether used to assess mental health in humans 24,25 , welfare in farm animals 26,27 , or distress in laboratory animals 28,29 (to mention just a few applications).…”