Causes and Development of PTSD
- soulsunleashed
- July 12, 2025
FREQUENTLY ASKED QUESTIONS
Can PTSD develop months after trauma?
Does everyone who experiences trauma develop PTSD?
Are certain people more prone to PTSD?
Can PTSD change the brain permanently?
KEY TERMS
Brain Structure and Function
Neuroimaging studies reveal key brain differences in people with PTSD:
Amygdala: Overactive, leading to heightened fear responses.
Hippocampus: Reduced volume, impairing memory processing and context discrimination.
Prefrontal Cortex: Underactive, affecting emotional regulation and decision-making.
These changes contribute to persistent fear, flashbacks, and exaggerated responses to triggers.
Genetics and Heritability
Genetic factors contribute to PTSD vulnerability:
Twin studies show heritability estimates between 30-40% (NIMH, 2024).
Variations in genes regulating stress hormones, like FKBP5, have been linked to increased PTSD risk.
However, genetics alone don’t determine who develops PTSD. Environmental factors remain crucial.
Hormonal Responses
Trauma alters the body’s hypothalamic-pituitary-adrenal (HPA) axis, the stress hormone system:
People with PTSD often show abnormal cortisol levels.
Excessive norepinephrine leads to hypervigilance and sleep disturbances.
These biological changes help explain the persistent anxiety and physical symptoms seen in PTSD.