A cluster analytic approach to examining the role of cortisol in the development of post-traumatic stress and dysphoria in adult traumatic injury survivors

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Key points:

An approach derived from the “gold standard” for clinical diagnoses involving PTSD was used to distinguish trauma-specific symptoms of PTSD versus dysphoria six to eight months after traumatic injury.

High levels of a stress hormone called cortisol, measured in the days after a traumatic injury, was associated with the development of dysphoria six months later, a symptom similar to depression.

By contrast, low levels of cortisol in the days after atraumatic injury was associated with an opposite pattern, in that it predicted the presence of PTSD symptoms six months later.

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PTSD is common, in that about 12 million U.S. adults live with post-traumatic stress disorder during any given year (National Center for PTSD, 2021). Approximately half of people with PTSD also suffer from Major Depressive Disorder ([MDD] Flory, 2015). It is unclear whether the presence of PTSD vs. MDD after trauma may be linked to differential biological mechanisms, in particular with respect to how people biologically respond to the stress of trauma.

Cortisol is the main stress hormone in humans and is created by the hypothalamic-pituitary-adrenal (HPA) Axis, the body’s normal biological response to stress. When this system is dysregulated, cortisol production can be increased or decreased, leading to life-altering symptoms.

In this study, acute cortisol was measured from the blood about 3 days after individuals experienced a traumatic injury in which they were admitted to the emergency department. Our sample included 172 traumatic injury survivors. We measured whether these individuals developed psychological symptoms, specifically symptoms of posttraumatic stress disorder (PTSD) and dysphoria, a symptom commonly experienced in MDD. Then, an analysis was performed to associate unique contribution of post-injury cortisol with severity of PTSD at six to eight months, and dysphoria severity for the same timeframe. Higher cortisol was evident in individuals who went onto develop just symptoms of dysphoria. By contrast, lower was associated with the development of both PTSD and dysphoria symptoms.

Such findings suggest that cortisol levels after injury may be a significant measure in trying to decipher whether individuals will go on to develop dysphoria versus PTSD symptoms.

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***Figure below depicts differences in cortisol among the four subgroups based on cluster analysis (Jayan et al., 2021). The Dysphoria subgroup exhibited significantly higher cortisol compared to all the other groups. The Severe comorbid subgroup exhibited significantly lower cortisol compared to the Resilient and Dysphoria subgroups; *p < 0.05, ***p < 0.001. Error bars represent 95% confidence interval.

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