550 TREATMENT OF SPECIFIC ANXIETY DISORDERS
effiCaCy of Cognitive therapy for ptsDIn recent years the heightened interest in PTSD and its treatment have led to a strong
empirical base for cognitive and cognitive- behavioral therapy for PTSD. Expert consen-
sus guidelines for treatment of PTSD consider cognitive therapy one of the most effec-
tive, first-line treatments for PTSD either alone or in combination with medication (Foa,
Davidson, & Frances, 1999). The treatment guidelines issued by the National Institute
for Clinical Excellence (NICE), which is sponsored by the British National Health Sys-
tem (NHS), recommends trauma- focused cognitive- behavioral therapy or eye movement
desensitization and reprocessing as preferred treatments for PTSD (NICE, 2005). DeRu-
beis and Crits- Christoph (1998) concluded that systematic exposure to trauma stimuli
was an efficacious empirically supported treatment for PTSD, while Chambless et al.
(1998) considered it a probably efficacious intervention. More recently Harvey, Bryant,
and Tarrier (2003) concluded in their review of outcome studies that CBT was clearly an
efficacious treatment for a range of traumas, while Hollon et al. (2006) reviewed CBT
outcome studies that demonstrated enduring treatment effects.
A sufficient number of randomized control trials (RCTs) have been conducted to
enable meta- analyses of the effectiveness of cognitive therapy alone or cognitive therapy
plus trauma- focused exposure (CBT) in PTSD. A well-known meta- analysis conducted
on 26 outcome studies revealed that exposure plus cognitive restructuring yielded a
mean pre- versus posttreatment effect size of 1.66 and 70% of treatment completers
no longer met diagnostic criteria for PTSD at posttreatment compared with 39.3% of
patients receiving a supportive therapy condition (Bradley, Greene, Russ, Dutra, & Wes-
ten, 2005). There were no significant differences in effectiveness between exposure only,
cognitive therapy plus exposure, and eye movement desensitization and reprocessing
(EMDR), although this conclusion was based on a small number of comparison studies.
Treatment for combat- related PTSD had the lowest effect size. In a more recent meta-
analysis of 38 RCTs, trauma- focused CBT, which is most like the cognitive therapy
protocol described in this chapter, was clinically superior to wait list and treatment-as-
usual conditions (Bisson et al., 2007). Moreover, CBT tended to have beneficial effects
on depression and anxiety as well as on PTSD symptoms, and both CBT and EMDR
may be slightly more effective than stress management or other therapies such as medi-
cation alone, although there was no evidence that CBT was significantly better than
EMDR. Once again both treatments produced more modest results with combat- related
PTSD.
A number of studies have shown that trauma- focused cognitive therapy or CBT
produces significantly greater improvement on symptom measures of PTSD, general-
ized anxiety, depression, and functional impairment than wait list control, treatment-
as-usual, or relaxation alone conditions, and these gains are maintained over 6-, 9-, or
12-month follow-up periods (e.g., Ehlers et al., 2005; Ehlers et al., 2003; Foa, Hembree,
et al., 2005; Marks, Lovell, Noshirvani, Livanou, & Thrasher, 1998; McDonagh et al.,
2005; Mueser et al., 2008; Resick, Nishith, Weaver, Astin, & Feuer, 2002). In a 5-year
follow-up Tarrier and Sommerfield (2004) found that no patients who received cognitive
therapy relapsed into a full episode of PTSD whereas 29% of the imaginal exposure only
group relapsed. This suggests that cognitive therapy for PTSD may have more enduring
effects than trauma- focused imaginal exposure alone. However, cognitive therapy may