title: Cognitive change predicts symptom reduction with cognitive therapy for posttraumatic stress disorder.
abstract: OBJECTIVE
  There is a growing body of evidence for the effectiveness of trauma-focused cognitive behavior therapy (TF-CBT) for posttraumatic stress disorder (PTSD), but few studies to date have investigated the mechanisms by which TF-CBT leads to therapeutic change. Models of PTSD suggest that a core treatment mechanism is the change in dysfunctional appraisals of the trauma and its aftermath. If this is the case, then changes in appraisals should predict a change in symptoms. The present study investigated whether cognitive change precedes symptom change in Cognitive Therapy for PTSD, a version of TF-CBT.
  
  
  METHODS
  The study analyzed weekly cognitive and symptom measures from 268 PTSD patients who received a course of Cognitive Therapy for PTSD, using bivariate latent growth modeling.
  
  
  RESULTS
  Results showed that (a) dysfunctional trauma-related appraisals and PTSD symptoms both decreased significantly over the course of treatment, (b) changes in appraisals and symptoms were correlated, and (c) weekly change in appraisals significantly predicted subsequent reduction in symptom scores (both corrected for the general decrease over the course of therapy). Changes in PTSD symptom severity did not predict subsequent changes in appraisals.
  
  
  CONCLUSIONS
  The study provided preliminary evidence for the temporal precedence of a reduction in negative trauma-related appraisals in symptom reduction during trauma-focused CBT for PTSD. This supports the role of change in appraisals as an active therapeutic mechanism.
authors.affiliation: Department of Psychology, King's College London, London, UK. b.kleim@psychologie.uzh.ch
authors.forename: Birgit
authors.initials: B
authors.lastname: Kleim
authors.forename: Nick
authors.initials: N
authors.lastname: Grey
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wild
authors.forename: Fridtjof W
authors.initials: FW
authors.lastname: Nussbeck
authors.forename: Richard
authors.initials: R
authors.lastname: Stott
authors.forename: Ann
authors.initials: A
authors.lastname: Hackmann
authors.forename: David M
authors.initials: DM
authors.lastname: Clark
authors.forename: Anke
authors.initials: A
authors.lastname: Ehlers
mesh_terms: D000328:Adult; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011237:Predictive Value of Tests; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome