524 TREATMENT OF SPECIFIC ANXIETY DISORDERS
Hypothesis 7
Avoidance of trauma- related cues and safety seeking will be more frequent in persistent
PTSD compared to non-PTSD states.
As in the other anxiety disorders, avoidance and reliance on safety seeking are con-
sidered important contributors to the persistence of PTSD symptoms. This last hypoth-
esis proposes a direct relationship such that greater avoidance and safety seeking con-
tributes to a more persistent, severe, and adverse posttraumatic state.
There is empirical evidence in support of this contention. Dunmore et al. (1999)
found that assault victims with persistent PTSD were significantly more likely to engage
in avoidance and safety seeking in the month after the assault than those without PTSD.
In a 9-month follow-up study, use of avoidance and safety seeking 1 month after an
assault predicted severity of PTSD at 9 months even after controlling for severity of
the assault (Dunmore et al., 2001). However, emotional numbing, which is a type of
avoidance common in PTSD, has had stronger support from self- report than experi-
mental studies. For example, in a study of autonomic and facial muscle response to
emotionally evocative pictures, Vietnam veterans with PTSD did not show augmented
or suppressed emotional response to pleasant or unpleasant picture stimuli, although
they did show reduced response to pleasant emotional stimuli after being primed with
trauma- related pictures (Litz et al., 2000). This latter effect would be consistent with
reduced response and possibly poorer cognitive processing of safety cues after exposure
to trauma- relevant information.
Clinician Guideline 12.20
In vivo exposure that targets reduction in avoidance and safety- seeking behaviors in trauma-
relevant situations and improvement in processing positive safety cues is an important ther-
apeutic ingredient of cognitive therapy of PTSD.Cognitive assessment anD Case formulationDiagnostic Interview and Symptom Measures
The SCID-IV (First et al., 1997) and ADIS-IV (Brown et al., 1994) both have PTSD
modules that closely adhere to the DSM-IV diagnostic criteria. The SCID-IV PTSD
module (or earlier SCID for DSM-III) has sound psychometric properties with (1) an
interrater reliability kappa of .66 and 78% diagnostic agreement (Keane et al., 1998),
(2) high convergent validity with other PTSD symptom measures, and (3) substantial
sensitivity (.81) and specificity (.98) (see Keane, Brief, Pratt, & Miller, 2007, for discus-
sion). However, the SCID-IV has been criticized for assessing symptoms based only on
the “worst event” experienced as well as relying on a trauma screen that may be inac-
curate (Keane et al., 2007).
The psychometric properties of the ADIS-IV PTSD module are promising but less
well established. Blanchard, Gerardi, Kolb, and Barlow (1986) reported an interrater
kappa of .86 (93% agreement) for the DSM-III version of the interview schedule. How-