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This article explores the intricate relationship between trauma and PTSD symptoms, shedding light on the factors that make some individuals more susceptible to this disorder and how research findings are offering new insights into its prevention and treatment.
PTSD Symptoms and their development through Trauma
Posttraumatic stress disorder (PTSD) is a challenging condition that can arise after experiencing traumatic events. While many individuals go through such trauma, only around 25-35% of them develop PTSD. It’s crucial to comprehend the factors that make certain individuals more susceptible to this disorder, as this understanding can greatly assist in both its prevention and treatment.
Glucocorticoids and Their Role in PTSD Symptoms
A new study, led by Carmen Sandi and Simone Astori at EPFL, delves into how PTSD development is influenced by glucocorticoids, the hormones released by our bodies in response to stress, including cortisol. This research provides valuable insights into the behavioral and biological characteristics linked to vulnerability to PTSD.
Examining Glucocorticoid Levels and Trauma
Carmen Sandi points out the variations in glucocorticoid levels released by individuals when they experience trauma. Low glucocorticoid levels are often observed in PTSD patients following trauma exposure, initially considered a consequence of the trauma itself. However, whether low glucocorticoid levels constitute a pre-existing risk factor for PTSD symptoms has remained a question for years. Yet, this inquiry has been challenging due to difficulties in collecting biological data before trauma occurs in humans and accessing relevant animal models for research.
Insights from Rat Models
To investigate the connection between a diminished hormonal response to trauma and PTSD symptoms, the researchers employed a genetically selected rat model that mimics individuals with reduced responses to cortisol. Their research methods included MRI scans to measure the size of different brain regions, training rats to associate cues with fear, monitoring sleep patterns, and examining brain activity.
The Multi-Trait Response to Low Glucocorticoid Responsiveness
Through these methods, the researchers discovered that a reduced response to glucocorticoids led to a “correlated multi-trait response.” This included impaired fear extinction in male rats, reduced hippocampal volume, and disruptions in rapid-eye movement sleep.
Treating Rats and Findings
Taking their research a step further, the team treated the rats with a form of cognitive and behavioral therapy similar to what humans receive to reduce their learned fears. After therapy, they administered corticosterone to the rats. The results were promising—excessive fear diminished, and disruptions in rapid-eye movement sleep were alleviated. Furthermore, the elevated levels of the stress-related neurotransmitter norepinephrine in the brain returned to normal.
Understanding the Mechanisms of PTSD Vulnerability
Carmen Sandi emphasizes the significance of their findings: “Our study offers compelling evidence that low glucocorticoid responsiveness directly contributes to the development of PTSD symptoms following exposure to traumatic experiences, particularly impaired fear extinction. Furthermore, it shows that low glucocorticoid levels play a causal role in the determination of other risk factors and symptoms that were previously only loosely connected to PTSD.”
Implications for PTSD Symptoms Research and Trauma Treatment
Silvia Monari, the study’s lead author, simplifies the findings, stating, “In simple terms, our research provides mechanistic evidence that individuals with low glucocorticoids, like cortisol in humans, are more likely to exhibit all the known vulnerability factors for developing PTSD. Additionally, it is causally involved in the difficulty of extinguishing traumatic memories.”
The Relevance to Complex Post-Traumatic Stress Disorder (C-PTSD)
It’s important to recognize that alongside Posttraumatic Stress Disorder (PTSD), there’s Complex Post-Traumatic Stress Disorder (C-PTSD). While our study primarily delves into classic PTSD, C-PTSD is another significant trauma-related condition, typically emerging from prolonged exposure to trauma, often of an interpersonal nature.
C-PTSD encompasses a broader spectrum of symptoms, including emotional dysregulation, distorted self-concept, and challenges in relationships. While our research primarily focuses on classic PTSD, the insights into glucocorticoid levels could also hold relevance for understanding C-PTSD. More targeted research is necessary, but these findings provide a foundation for comprehending the common factors underpinning trauma-related disorders.
