Etiology of PTSD

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=M5UE69o99lo

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=rYc7Ey-kO-0