Psychoneuroendocrinology (2015) 59, 123—133

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Hair cortisol concentrations and cortisol stress reactivity predict PTSD symptom increase after trauma exposure during military deployment Susann Steudte-Schmiedgen a,∗, Tobias Stalder a, Sabine Schönfeld b, Hans-Ulrich Wittchen b, Sebastian Trautmann b, Nina Alexander a, Robert Miller a, Clemens Kirschbaum a a

Institute of Biological Psychology, Technische Universität Dresden, 01062 Dresden, Germany Institute of Clinical Psychology and Psychotherapy & Center of Clinical Epidemiology and Longitudinal Studies, Technische Universität Dresden, 01187 Dresden, Germany

b

Received 27 January 2015; received in revised form 24 April 2015; accepted 12 May 2015

KEYWORDS Posttraumatic stress disorder; Traumatization; Hair; Saliva; Cortisol; Trier Social Stress Test

Summary Background: Previous evidence on endocrine risk markers for posttraumatic stress disorder (PTSD) has been inconclusive. Here, we report results of the first prospective study to investigate whether long-term hair cortisol levels and experimentally-induced cortisol stress reactivity are predictive of the development of PTSD symptomatology in response to trauma during military deployment. Methods: Male soldiers were examined before deployment to Afghanistan and at a 12-month post-deployment follow-up using dimensional measures for psychopathological symptoms. The predictive value of baseline (i) hair cortisol concentrations (HCC, N = 90) and (ii) salivary cortisol stress reactivity (measured by the Trier Social Stress Test, N = 80) for the development of PTSD symptomatology after being exposed to new-onset traumatic events was analyzed. Results: Baseline cortisol activity significantly predicted PTSD symptom change from baseline to follow-up upon trauma exposure. Specifically, our results consistently revealed that lower HCC and lower cortisol stress reactivity were predictive of a greater increase in PTSD symptomatology in soldiers who had experienced new-onset traumatic events (explaining 5% and 10.3%



Corresponding author at: Technische Universität Dresden, Department of Psychology, Institute of Biological Psychology, Zellescher Weg 19, 01062 Dresden, Germany. Tel.: +49 351 463 35911; fax: +49 351 463 37274. E-mail address: [email protected] (S. Steudte-Schmiedgen). http://dx.doi.org/10.1016/j.psyneuen.2015.05.007 0306-4530/© 2015 Elsevier Ltd. All rights reserved.

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S. Steudte-Schmiedgen et al. of variance, respectively). Longitudinal analyses revealed an increase in HCC from baseline to follow-up and a trend for a negative relationship between HCC changes and the number of newonset traumatic events. Additional pre-deployment analyses revealed that trauma history was reflected in lower HCC (at trend level) and that HCC were negatively related to stressful load. Conclusions: Our data indicate that attenuated cortisol secretion is a risk marker for subsequent development of PTSD symptomatology upon trauma exposure. Future studies are needed to confirm our findings in other samples. © 2015 Elsevier Ltd. All rights reserved.

1. Introduction While epidemiological studies suggest that 41—86% of all people experience at least one traumatic event during their lifetime, only a relative minority ( .215, see Table 1). Further, no differences were seen between predictive samples and the overall baseline sample, except for a higher probability to be enlisted in higher ranks for soldiers included in the predictive HCC and TSST analysis, respectively (ps < .01). All participants provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and was approved by the ethics committee of the Technische Universität Dresden Medical School (EK 72022010).

2.2. Clinical and psychological measures The respondent-booklets of the DIA-X/M-CIDI were supplemented with interviewer and self-reported questions and modules relevant for the study aims and the military

Cortisol predicts PTSD symptom increase context. Among others, information on sociodemographic variables (sex, age, smoking status, body mass index, alcohol consumption), hair-specific characteristics (washes per week, curls/waves, hair treatments) and participants’ health (medication intake, physical diseases) were obtained. As part of the CIDI-PTSD module we assessed for all participants both the number of ‘‘stressful’’ (A1 criteria of DSM-IV for PTSD) and the number of qualifying ‘‘traumatic’’ (A1 and A2 criteria of DSM-IV for PTSD) events. In addition, the MHAT-IV list (Wittchen and Schönfeld, 2009) was incorporated to assess the number and frequency of combat-related experiences. The PCL (Weathers et al., 1997) was used to measure the severity of overall PTSD symptoms with sum scores ranging from 17 to 85, including the three subscales reflecting DSM-IV-TR cluster criteria for PTSD (intrusions, avoidance, hyperarousal). The severity of maltreatment in childhood was measured by the Childhood Trauma Questionnaire (CTQ, Wingenfeld et al., 2010). Additionally, the revised CIDI-Depression Screening Questionnaire (DSQ-34, Wittchen and Schönfeld, 2009) was used to assess the severity of depressiveness over the last week.

2.3. Sample collection and preparation 2.3.1. Hair cortisol analysis Hair strands (∼3 mm diameter) were taken scalp-near from a posterior vertex position. HCC in the proximal 2-cm hair segment were measured reflecting integrated cortisol secretion over the 2 month-period prior to hair sampling (reviewed in Stalder and Kirschbaum, 2012). HCC were determined via liquid chromatography tandem mass spectrometry. Detailed information on the analytical protocol is provided in Gao et al. (2013). 2.3.2. Cortisol stress reactivity The Trier Social Stress Test (TSST; Kirschbaum et al., 1993) is an effective standardized protocol for the reliable induction of acute psychosocial stress under laboratory conditions (reviewed in Allen et al., 2014; Foley and Kirschbaum, 2010). A detailed description of the experimental procedure is provided in Wittchen et al. (2012b). In brief, the TSST consists of a public speaking (5 min) and a mental arithmetic task (5 min) performed in front of two evaluating panelists. Participants were instructed to refrain from smoking, eating and drinking anything but water 60 min prior to the TSST. Saliva samples were collected immediately before the TSST as well as 1, 10 and 20 minutes after the TSST using Salivette devices (Sarstedt, Rommelsdorf, Germany). Samples were stored at −20 ◦ C in a laboratory freezer. After thawing, saliva samples were centrifuged for 10 min at 4000 rpm. Salivary cortisol concentrations were analyzed using a commercially available luminescence assay (LIA, IBL-Hamburg, Germany).

2.4. Data exclusion and statistical analysis Analyses were performed using SPSS for Windows, version 22 (IBM, Chicago, Illinois). Hair cortisol and salivary cortisol data were not normally distributed, thus log transformations were applied to reduce skewness statistics. Changes in clinical characteristics from baseline to follow-up were

127 examined by using repeated measures analysis of covariance (ANCOVA) with baseline values as covariate. Group comparisons in sociodemographic and hair-related characteristics between soldiers who had experienced at least one lifetime traumatic event before deployment and non-traumatized soldiers were conducted using t-tests (continuous variables) and Fisher’s exact tests (dichotomous variables). In case of significant group differences, these variables were subsequently included as covariates. For HCC analyses, data from three participants were excluded due to outlying values of more than three standard deviations above the mean (see Fig. 1). A one-way ANOVA was carried out to examine the impact of the experience of at least one lifetime traumatic event on HCC before deployment. Spearman correlations were further applied to examine HCC relationships with the number of stressful and traumatic events as well as CTQ scores. A stepwise regression analysis with PCL change scores as dependent variable and initial PCL scores, baseline HCC and the number of new-onset and baseline traumatic events as independent variables was conducted. As a second step, the interaction term between baseline HCC × number of new-onset traumatic events was entered in the model to examine the predictive value of HCC for the development of PTSD symptoms as a function of trauma exposure. F-tests were used to test whether the inclusion of the interaction term contributed to a significant increase in the amount of explained variance. Due to multicollinearity issues isolated test statistics are not interpretable. To investigate associations between intra-individual changes in HCC and PCL scores as well as in the number of traumatic events, change scores were computed for respective variables by subtracting baseline from follow-up values. Relationships between these scores were then examined by using partial correlational analyses, controlling for respective baseline values. Further, HCC changes from baseline to follow-up were analyzed by conducting repeated measures ANCOVA with baseline HCC values as covariate. For cortisol stress reactivity, data from five participants were excluded due to outlying values of more than three standard deviations above the mean (see Fig. 1). Salivary cortisol data were analyzed by repeated measures ANCOVA with baseline cortisol values as covariate across the complete sample. To test for the influence of the experience of at least one lifetime traumatic event on cortisol stress reactivity before deployment a two-way repeated measures ANCOVA with measurement time [4] as within-subject factor and group [2] as between-subject factor with baseline cortisol values as covariate was conducted. The area under the curve with respect to increase (AUCI ) was calculated as a composite measure reflecting the cortisol stress response to the TSST (Pruessner et al., 2003). Spearman correlations were conducted to examine relationships between AUCI salivary cortisol and the number of stressful and traumatic events as well as CTQ scores. As described for HCC, a stepwise regression analysis was conducted, examining the predictive value of AUCI salivary cortisol together with initial PCL scores, the number of new-onset and baseline traumatic events for PCL change scores from baseline to follow-up. Again, it was examined whether the inclusion of the AUCI × number of new-onset traumatic event interaction (model 2) resulted in a significant increase in the amount of

128 Table 2

S. Steudte-Schmiedgen et al. Trauma-related and psychological characteristics at baseline and follow-up. HCC sample (N = 90) Follow-up

p*

Follow-up

p*

2.91 (2.10)

4.57 (2.97)

Hair cortisol concentrations and cortisol stress reactivity predict PTSD symptom increase after trauma exposure during military deployment.

Previous evidence on endocrine risk markers for posttraumatic stress disorder (PTSD) has been inconclusive. Here, we report results of the first prosp...
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