Anxiety Disorders 321
themselves or their families have fewer emotional resources available to cope with a
traumatic event and so are less likely than more fortunate individuals to weather it
without developing PTSD (Mezey & Robbins, 2001).
In addition, those who are at a socioeconomic disadvantage may be more likelyto experience trauma (Breslau et al., 1998; Himle et al., in press). For instance,
poorer people are more likely to live in high-crime areas and so are more likely to
witness crimes or become crime victims (Norris et al., 2003).
Social Support
People who receive support from others immediately after a trauma have a lower
risk of developing PTSD (Kaniasty & Norris, 1992; Kaniasty, Norris & Murrell,
1990). For example, people who have experienced trauma during military service
have a lower risk of developing PTSD if they have strong social support upon re-
turning home (Jakupcak et al., 2006; King et al., 1999).
Cultural Expression of Symptoms
A person’s culture can help determine which PTSD symptoms are more prominent.
Cultural patterns might “teach” one coping style rather than another (Marsella
et al., 1996). For example, Hurricane Paulina in Mexico and Hurricane Andrew in
the United States were about equal in force, but the people who developed PTSD
afterward did so in different ways (after controlling for the severity of an individual’s
trauma): Mexicans were more likely to have intrusive symptoms (Criterion B in Table
7.17), such as fl ashbacks about the hurricane and its devastation, whereas Americans
were more likely to have arousal symptoms (Criterion D in Table 7.17), such as an
exaggerated startle response or hypervigilance (Norris, Perilla, & Murphy, 2001). A
similar fi nding was obtained from a study comparing Hispanic Americans to Euro-
pean Americans after Hurricane Andrew (Perilla, Norris, & Lavizzo, 2002).
FEEDBACK LOOPS IN ACTION:
Understanding Posttraumatic Stress Disorder
Neurological, psychological, and social differences among individuals lead to their
different responses to traumatic events (Bowman, 1999). Neurological factors
can make some people more vulnerable to developing PTSD after a trauma. For
example, in a study of those training to be fi refi ghters, trainees who had a larger
startle response to loud bursts of noise at the beginning of training were more
likely to develop PTSD after a subsequent fi re-related trauma (Guthrie & Bryant,
2005). In another study of male Vietnam veterans who were fraternal or identi-
cal twins, researchers found that willingness to volunteer for combat and to ac-
cept riskier assignments is partly heritable (neurological factor; Lyons et al., 1993).
This heritability may involve the dimension of temperament called novelty seeking
(see Chapter 2). Someone high in novelty seeking pursues activities that are excit-
ing and very stimulating, and a person with this characteristic may be more likely
to volunteer for risky assignments (psychological factor), increasing the chance of
encountering certain kinds of trauma. This means that neurological factors can in-
fl uence both psychological and social factors, which in turn can increase the risk
of trauma. At the same time, when a traumatic event is more severe (social factor),
other types of factors are less important in infl uencing the onset of PTSD (Keane &
Barlow, 2002).
Furthermore, ways of viewing the world and other personality traits (psycho-logical factors) can infl uence the level of social support that is available to a per-
son after suffering trauma (social factor). Because shy people are less likely have a
wide social network, they tend to have less social support than do people who seek
out social activities. Even when a traumatized person has suffi cient social support, if
others encourage him or her to suppress thoughts of the event (“just don’t think about
it any more”), he or she might inadvertently increase the amount of attention paid to
the traumatic experience—which increases the risk of PTSD. Figure 7.17 illustrates
these factors and their feedback loops.
P SNP SN