Longitudinal treatment mediation of traditional cognitive behavioral therapy and acceptance and commitment therapy for anxiety disorders.
OBJECTIVE
To assess the relationship between session-by-session putative mediators and treatment outcomes in traditional cognitive behavioral therapy (CBT) and acceptance and commitment therapy (ACT) for mixed anxiety disorders.


METHODS
Session-by-session changes in anxiety sensitivity and cognitive defusion were assessed in 67 adult outpatients randomized to CBT (n = 35) or ACT (n = 32) for a DSM-IV anxiety disorder.


RESULTS
Multilevel mediation analyses revealed significant changes in the proposed mediators during both treatments (p < .001, d = .90-1.93), with ACT showing borderline greater improvements than CBT in cognitive defusion (p = .05, d = .82). Anxiety sensitivity and cognitive defusion both significantly mediated post-treatment worry; cognitive defusion more strongly predicted worry reductions in CBT than in ACT. In addition, cognitive defusion significantly mediated quality of life, behavioral avoidance, and (secondary) depression outcomes across both CBT and ACT (p < .05, R(2) change = .06-.13), whereas anxiety sensitivity did not significantly mediate other outcomes.


CONCLUSIONS
Cognitive defusion represents an important source of therapeutic change across both CBT and ACT. The data offered little evidence for substantially distinct treatment-related mediation pathways.
Department of Psychology and Neuroscience, University of Colorado Boulder, 345 UCB Muenzinger, Boulder, CO 80309-0345, USA. Joanna.Arch@Colorado.edu
Joanna J
JJ
Arch
Kate B
KB
Wolitzky-Taylor
Georg H
GH
Eifert
Michelle G
MG
Craske
D000328:Adult; D001008:Anxiety Disorders / Q000628:therapy*; D001521:Behavior Therapy / Q000379:methods*; D015928:Cognitive Behavioral Therapy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010353:Patient Education as Topic; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult