Hair cortisol predicts avoidance behavior and depressiveness after first-time and single-event trauma exposure in motor vehicle crash victims

Figures & data

Table 1. Comparison of MVC survivors with at least one vs. no SCID diagnosis. Mean (SD) are listed except where noted.

			Statistics
	SCID diagnosis	No SCID diagnosis	F/χ^2	p
Sociodemographics
Sex, female, n (%)^b	13 (92.9)	33 (68.8)	2.983	.155
Age in years	43.75 (13.51)	43.99 (12.93)	0.004	.950
Education, n (%)^a^,^b
University-entrance diploma	5 (35.7)	20 (41.7)
Secondary education/10 classes	8 (57.1)	25 (52.1)
Eight classes	0 (0.00)	2 (4.2)	0.723	.854
BMI (kg/m^2)	26.31 (5.46)	26.42 (5.26)	0.005	.943
Smokers, n (%)^b	6 (42.8)	3 (6.3)	11.410	.003**
Cigarettes smoked per day	3.0 (4.40)	0.45 (1.95)	10.825	.002**
Oral contraceptive use, n (%)^b	3 (23.1)	8 (24.2)	0.142	.703
ISS	3.00 (3.113)	5.87 (8.36)	1.567	.216
Clinical measures (initial)
PDS	8.86 (7.20)	4.77 (4.87)	6.038	.017*
IES-R total	−2.43 (1.66)	−3.30 (1.15)	4.897	.031*
IES-R intrusion	9.43 (9.12)	4.87 (5.73)	5.100	.028*
IES-R avoidance	9.57 (10.74)	6.57 (7.05)	1.509	.224
IES-R hyperarousal	9.64 (8.59)	4.68 (5.65)	6.455	.014*
BDI-II	13.29 (11.06)	6.21 (7.57)	7.536	.008**
Hair cortisol concentration (HCC)
HCC pre-MVC (pg/mg)	17.36 (15.66)	21.60 (15.15)	0.832	.365
HCC post-MVC (pg/mg)	26.01 (17.99)	20.07 (14.77)	1.572	.215

BMI: body mass index; ISS: Injury Severity Scale; PDS: Posttraumatic Diagnostic Scale; IES-R: Impact of Event Scale – Revised; BDI: Beck Depression Inventory II.

Cigarettes smoked per day includes both smokers and nonsmokers.

^an= 2 missing values.

^bχ²-test.

^* p≤.05.

^** p≤.01.

Table 2. Correlation matrix of the relationship between hair cortisol and clinical measures.

Variable	Pre-MVC HCC (pg/mg)	Post-MVC HCC (pg/mg)
Pre-MVC HCC		0.485***
Post-MVC HCC	0.485***
Age	0.102	0.282*
Sex	0.209	0.211
BMI	–0.130	0.134
ISS	0.435**	0.171
Initial total PDS	0.123	0.244^†
Initial total IES-R	0.045	0.259*
Initial IES-R intrusion	0.023	0.193
Initial IES-R avoidance	–0.028	0.148
Initial IES-R hyperarousal	0.074	0.282*
Initial BDI-II	0.062	0.124
Follow-up total PDS	–0.012	0.138
Follow-up total IES-R	0.095	0.246^†
Follow-up IES-R intrusion	–0.161	0.077
Follow-up IES-R avoidance	0.145	0.208
Follow-up IES-R hyperarousal	0.021	0.218^†
Follow-up BDI-II	0.254*	0.372**

HCC: hair cortisol concentration; ISS: Injury Severity Scale; PDS: Posttraumatic Diagnostic Scale; IES-R: Impact of Event Scale – Revised; BDI: Beck Depression Inventory II; follow-up: three months post-MVC.

Pearson’s correlational coefficient r (two-tailed) is listed.

^* p≤.05.

^** p≤.01.

^*** p≤.001.

^† .05≤p≤.10.

Table 3. Linear regression analyses predicting psychological symptoms 3 months post-crash from hair cortisol concentrations (HCC) and initial psychological symptoms immediately after the motor vehicle crash (MVC).

Dependent	F	Predictor	B	SE	β	p	R^2 adjusted
Follow-up total PDS	6.036					.000***	0.255
		Initial total PDS	0.393	0.087	0.520	.000***
		HCC pre-MVC	0.592	1.049	0.076	.575
		HCC post-MVC	0.356	0.961	0.048	.713
		ISS	–0.172	0.091	–0.227	.065^†
Follow-up total IES-R	9.333					.000***	0.361
		Initial total IES-R	0.475	0.085	0.594	.000***
		HCC pre-MVC	0.331	0.227	0.183	.150
		HCC post-MVC	0.035	0.209	0.021	.866
		ISS	–0.022	0.020	–0.124	.272
Follow-up IES-R intrusion	4.740					.002***	0.202
		Initial IES-R intrusion	0.412	0.104	0.466	.000***
		HCC pre-MVC	–0.611	1.309	–0.065	.642
		HCC post-MVC	0.581	1.196	0.066	.629
		ISS	–0.124	0.113	–0.137	.277
Follow-up IES-R avoidance	12.152					.000***	0.431
		Initial IES-R avoidance	0.592	0.088	0.667	.000***
		HCC pre-MVC	2.700	1.296	0.247	.042*
		HCC post-MVC	–0.289	1.173	–0.028	.806
		ISS	–0.043	0.112	–0.040	.705
Follow-up IES-R	7.125					.000***	0.293
hyperarousal		Initial IES-R hyperarousal	0.407	0.087	0.528	.000***
		HCC pre-MVC	0.930	1.204	0.102	.443
		HCC post-MVC	0.540	1.117	0.062	.631
		ISS	–0.149	0.105	–0.167	.160
Follow-up BDI-II	18.983					.000***	0.549
		Initial BDI-II	0.538	0.075	0.640	.000***
		HCC pre-MVC	2.121	1.275	0.175	.102
		HCC post-MVC	2.436	1.158	0.212	.040**
		ISS	–0.214	0.112	–0.181	.060^†

PDS: Posttraumatic Diagnostic Scale; initial: self-rated clinical measures obtained immediately after the traffic crash; HCC: hair cortisol concentration; ISS: Injury Severity Scale; IES-R: Impact of Event Scale – Revised; BDI: Beck Depression Inventory II.

^** p≤.01.

^*** p≤.001.

^† .05≤p≤.10.

Figure 1. Mean (±SE) hair cortisol concentrations pre- and post-crash in individuals who developed an anxiety or affective disorder after a motor vehicle crash and those who did not, accounting for baseline group differences in cortisol.