Neurobiology of PTSD and implications for treatment: An overview

Abstract

T raumatic events accompany our everyday life in the form subjective painful losses and wounding: It may be the loss of a home pet, the loss of a job, robbery, a car accident, natural disasters, severe illness, the death of a beloved person, emotional neglect and abuse, betrayal, bullying, sexual abuse, rape, an earthquake, war, a terrorist attack. According to statistics one out of two persons will be exposed to a life-threatening event during lifetime (1). Some of them will be able to overcome this experience; some will be severely affected in the long term. Relevant studies indicate that about 7% of Americans have a prevalence to develop a Post-Traumatic Stress Disorder (PTSD) at some point of their lives. According to statistical data men are more often exposed to traumatic events than women, but women are more likely to suffer from a PTSD disorder (2,3). Respective data for Greece are at this time not available. Nevertheless, the refugees' crisis we are facing as a hosting country arises the issue of PTSD to a first line social problem that we have to face in terms of policy measures and treatment options. How can Neurobiology contribute to the understanding of what happens in body and mind of a person suffering from PTSD? Can neurobiological findings reveal a new perspective in the treatment of PTSD beyond pharmacotherapy and classical psychotherapeutic approaches that might contribute to develop effective psychotherapeutic interventions? What does the experience of PTSD mean for the offspring of PTSD sufferers? From a traumatic experience to PTSDExtreme stressful situations in life are addressed by an instinctive "fight or flight" response in order to assure survival. Alerting sensory environmental information reaches the brain and enters the amygdala, the operation center of the brain in the case of extreme stressful situations that is responsible for the activation of the hypothalamic -pituitary adrenal axis (HPA) and the sympathetic nervous system (SNS). This activation produces multiple effects in body and mind in order for the individual to cope with the stressors. Via the SNS system the adrenal glands release hormones called catecholamines into the blood causing increased blood pressure, glucose levels and heart rate in order to support the body to "fight or fly". At the same time the hypothalamus, when stimulated releases neuropeptides that lead to the discharge of cortisol that binds the glucocorticoid receptors in the brain and reduces stress responses (4). Usually the stress response function contributes to the adaptation to threat and restores the homeostasis of the organism with an extinction of these reactions when stimuli are not present any more. Traumatic experiences are triggered by perceived overwhelming danger and are accompanied by intense feelings of fear, horror and helplessness. Such situations may lead to a dysregulation of the described underlying biological stress mechanisms known as the "fear circuitry" leading to stress related symptoms like PTSD. The state of chemical dysregul...

Post-traumatic stress disorder (PTSD) as a systemic disorder: Pathways to cardiovascular disease.

“…The question arises as to the significance of these many physiological and disease correlates for the conceptualization and understanding of PTSD. From the point of view of clinical neuroscience, the brain and CNS effects of PTSD have received considerable attention (Bremner, 2016; Fenster et al, 2018; Sakellariou & Stefanatou, 2017). However, increasing evidence indicates that, because of its wide-ranging physiological effects, PTSD may be a whole-body, systemic disorder “in disguise” (Michopoulos et al, 2016), with the psychological diagnostic criteria being just “the tip of the iceberg.” These systemic changes involve not just the brain and behavior, but have effects spanning multiple biological components (Bukhbinder & Schulz, 2016).…”

“…One of the hallmark characteristics of PTSD is chronic dysregulation of the neurohormonal systems that are part of the stress response (Bremner, 2016; Flory & Yehuda, 2018; Vaccarino et al, 2014). Relative to healthy controls, peripheral cortisol levels are reduced at rest; however, during trauma-related stimuli, cortisol release increases, and there is increased reactivity as measured by sympathetic activation, heart rate, catecholamine release, and blood pressure (Bremner, 2016; Sakellariou & Stefanatou, 2017). Among other CNS mechanisms and abnormalities in stress-related brain regions (e.g., the amygdala and hippocampus; Bremner, 2016), PTSD is also associated with alterations in the endocannabinoid system, which is involved in HPA axis responses to stress and the release of cortisol (Neumeister et al, 2013).…”

Post-Traumatic Stress Disorder (PTSD) as a Systemic Disorder: Pathways to Cardiovascular Disease. Article in press, HEALTH PSYCHOLOGY, 2021.

“…The question arises as to the significance of these many physiological and disease correlates for the conceptualization and understanding of PTSD. From the point of view of clinical neuroscience, the brain and CNS effects of PTSD have received considerable attention (Bremner, 2016;Fenster et al, 2018;Sakellariou & Stefanatou, 2017). However, increasing evidence indicates that, because of its wide-ranging physiological effects, PTSD may be a whole-body, systemic disorder "in disguise" (Michopoulos et al, 2016), with the psychological diagnostic criteria being just "the tip of the iceberg."…”

“…In addition, the temporal relationship between PTSD and inflammation is not well understood (Hori & Kim, 2019). Increased levels of circulating pro-inflammatory cytokines have been associated with sympathetic nervous system activation and exaggerated cardiovascular reactions to mental stressors in individuals with PTSD (Hori & Kim, 2019;Sakellariou & Stefanatou, 2017). This provides support for a bi-directional relationship between inflammation and cardiovascular and autonomic nervous system responses in PTSD.…”

“…One of the hallmark characteristics of PTSD is chronic dysregulation of the neurohormonal systems that are part of the stress response (Bremner, 2016;Flory & Yehuda, 2018;Vaccarino et al, 2014). Relative to healthy controls, peripheral cortisol levels are reduced at rest; however, during trauma-related stimuli, cortisol release increases, and there is increased reactivity as measured by sympathetic activation, heart rate, catecholamine release, and blood pressure (Bremner, 2016;Sakellariou & Stefanatou, 2017). Among other CNS mechanisms and abnormalities in stress-related brain regions (e.g., the amygdala and hippocampus) (Bremner, 2016), PTSD is associated with alterations in the endocannabinoid system, which is involved in HPA axis responses to stress and the release of cortisol (Neumeister et al, 2013).…”