Biochemical changes in the brain and body have been observed in majority of people diagnosed with Post-traumatic Stress Disorder. In laboratory studies it was seen that cortisol secretion in the urine is decreased, while catecholamine (norepineprine and epinephrine) is elevated in PTSD cases. Consequently, norepinephrine/cortisol level is higher than in normal individuals. On the other hand, catecholamine level in the brain is low, whereas corticotrophin-releasing factor (CRF) concentration is high. These findings suggest abnormality in the hypothalamic-pituitary-adrenal axis.
The key areas of the brain that are implicated in the development of PTSD are amygdala, prefrontal cortex and hippocampus.
- Amygdala is associated with the formation of emotional memories, especially fear-related. Research has shown that traumatic stimuli lead to fear conditioning which results to activation of amygdala, hypothalamus, locus cereleus, periaqueductal gray and parabrachial nucleus and its accompanying neurotransmitters. Thus, the symptoms of PTSD are produced.
- The Vietnam Head Injury Study showed that damage to the prefrontal cortex may actually be protective against later development of PTSD.
- Gurvits et al found out that combat veterans who suffered from PTSD had 20% reduction in the volume of their hippocampus compared to veterans who were not afflicted with it.
- Post-traumatic Stress Disorder. Wikipedia
- Post-traumatic Stress Disorder Overview. Medscape
- Post-traumatic Stress Disorder Diagnosis. Medscape
Post-traumatic Stress Disorder Overview
How to diagnose Post-traumatic Stress Disorder