500 TREATMENT OF SPECIFIC ANXIETY DISORDERS
traumatic experience (Breslau et al., 1998; Eriksson, Vande Kemp, Gorsuch, Hoke, &
Foy, 2001; see Vogt, King, & King, 2007). Furthermore, closer geographic proximity
to a traumatic community event, such as the 9/11 terrorist attack or proximity to the
epicenter of an earthquake, is associated with higher rates of PTSD (e.g., Galea et al.,
2002; Pynoos et al., 1993).
There is some evidence that PTSD increases with the severity of the traumatic event
(Brewin et al., 2000; Lauterbach & Vrana, 2001; Pynoos et al., 1993), although others
have concluded that evidence for a dose– response relationship is inconsistent (McNally,
2003a; Rosen & Lilienfeld, 2008). Trauma severity, defined in terms of combat expo-
sure, is the most significant predictor for risk of developing PTSD or its symptoms in
military samples (e.g., Hoge et al., 2006; Kulka et al., 1990; Lee, Vaillant, Torrey, &
Elder, 1995; Vogt, Samper, King, King, & Martin, 2008). In addition the perception
that one’s life was in danger during the traumatic event or being threatened by others
(Hollifield et al., 2008; Jeon et al., 2007; Ozer et al., 2003; Ullman et al., 2007) as well
as events that cause injury are related to higher rates of PTSD (Rasmussen, Rosenfeld,
Reeves, & Keller, 2007). Finally, certain types of trauma that involve severe interper-
sonal threat and danger, such as rape, sexual and physical assault, and childhood abuse,
are particularly toxic for PTSD and its symptoms (e.g., Breslau et al., 1998; Creamer et
al., 2001; Norris, 1992; Resnick et al., 1993; Seedat et al., 2004; Vrana & Lauterbach,
1994). On the other hand, traumatic stressors like motor vehicle accidents, natural disas-
ters, and witnessing or learning about traumas to others appear to be associated with a
lower prevalence of PTSD (Creamer et al., 2001; Jeon et al., 2007; Norris, 1992).
Certain emotional responses at the time of the trauma predict subsequent develop-
ment of PTSD. As discussed previously, the presence of ASD increases risk for PTSD or
posttrauma symptoms (Brewin et al., 1999; Bryant & Harvey, 1998; Harvey & Bryant,
1998b), as does presence and severity of early PTSD-related symptoms (e.g., avoidance
and numbing symptoms) or combat stress reactions (e.g., Koren, Arnon, & Klein, 1999;
North et al., 1999; Solomon & Mikulincer, 2007). Individuals who report intense nega-
tive emotional responses such as fear, helplessness, horror, guilt, or shame during or
immediately after the trauma have the higher levels of PTSD (Ozer at al., 2003). Finally,
occurrence of dissociative symptoms or panic attacks around the time of the trauma
may be a significant predictor of subsequent PTSD (Galea et al., 2002; Ozer et al., 2003;
see Bryant, 2007, for contrary view).
Posttrauma Risk Factors
A low level of perceived social support including negative social reactions from others
is a strong predictor of subsequent PTSD symptoms and disorder (Brewin et al., 2000;
Galea et al., 2002; Ozer et al., 2003; Ullman et al. 2007). On the other hand, a high
level of social support might mitigate the negative effects of exposure to life- threatening
events (Corneil et al., 1999; Eriksson et al., 2001). In addition certain coping responses
have been associated with higher PTSD including denial, self-blame, seeking social sup-
port, delayed disclosure, and disengagement from coping efforts (Silver et al., 2002;
Ullman et al., 2007). Long-term negative consequences resulting from the trauma such
as losing one’s job might increase risk for PTSD (Galea et al. 2002). And finally certain
cognitive variables have been predictive of PTSD such as overestimated threat apprais-
als, lower perceived safety, absence of optimism, detachment, mental defeat, and nega-