Etiology of PTSD
Biological Causes
– Role of Noradrenalin: increased levels = more
open expression of emotion
• Geracioti (2001): PTSD subjects had higher NorAd levels
than non-PTSD subjects; adrenal stimulation = panic
attacks (70%) and flashbacks (40%) vs. 0% in both
controls
• Bremner (1998): PTSD subjects had increased
sensitivity of Norad receptors
• As cortisol levels decrease, norepinephrine levels increase
resulting in an inability to regulate and recover from
fight/flight responses
Brain Areas Affected by PTSD
Genetic Implications
• Kolassa (2010): Val158Met polymorphism, gene for encoding
the enzyme catechol-O-methyltransferase (COMT) levels
affect Norad and Dopamine release during stress
• Helps explain how two people can experience the same
trauma and not both show symptoms of PTSD
Cognitive causes
–Thoughts of “lack of control” suggest external
locus of control and survivor guilt
–Intrusive/pervasive thoughts come from “cue
dependent memory” (Berwin et al 1996)
• Rizzo: flooding therapy, “virtual Iraq” aided
coping, recovery and “Habituation” (gradual
fading of stress reactions)
–Internal locus of control reduces PTSD;
External LOC increases PTSD
• Sutker et al (1995): soldiers with purpose/commitment
to military/mission have lower rates of PTSD (Internal)
• Can be linked to attributional style and Beck’s “cognitive
schema” ideas on depression (Internal)
• Suedfeld (2003): Holocaust survivors with external LOC
more likely than controls to experience PTSD and also
show low trust and a skeptical world view
• http://www.youtube.com/watch?v=M5UE69o99l
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Sociocultural causes
– Suggests racism/prejudice/oppression are
predisposing factors
• Roysircar (2000): meta analysis showed ethnic
differences in PTSD rates for Vietnam vets; black
20.6%, Hispanic 27.6%, white 13%
• Dyregov: Rwandan kids: threatened with death #1
cause of intrusive thoughts and withdrawal behavior
• Bosnian research 1998: 73% of girls (higher due to
additional threat of rape, Kaminer et al 2000), 35%
of boys from Sarajevo showed PTSD
– Somatic symptoms of PTSD commonly treated across all
cultures
• Body Memory Symptoms: non-western, physical
ailments solely from psychological causes (see
Somatoform disorders)
Gender Considerations
• Horowitz et al (1995): risk is 5x greater for women than men
• Breslau et al (1991): 1007 kids exposed to violence PTSD rates: 11.3%
in girls, 6% in boys
• Different symptoms: Men show irritability, impulsiveness and
aggression, substance abuse (external symptoms); women show
numbing, withdrawal and avoidance/anxiety (internal symptoms)
• http://www.youtube.com/watch?v=rYc7EykO-0