Respiratory and cognitive mediators of treatment change in panic disorder: evidence for intervention specificity.
OBJECTIVE
There are numerous theories of panic disorder, each proposing a unique pathway of change leading to treatment success. However, little is known about whether improvements in proposed mediators are indeed associated with treatment outcomes and whether these mediators are specific to particular treatment modalities. Our purpose in this study was to analyze pathways of change in theoretically distinct interventions using longitudinal, moderated mediation analyses.


METHODS
Forty-one patients with panic disorder and agoraphobia were randomly assigned to receive 4 weeks of training aimed at altering either respiration (capnometry-assisted respiratory training) or panic-related cognitions (cognitive training). Changes in respiration (PCO₂, respiration rate), symptom appraisal, and a modality-nonspecific mediator (perceived control) were considered as possible mediators.


RESULTS
The reductions in panic symptom severity and panic-related cognitions and the improvements in perceived control were significant and comparable in both treatment groups. Capnometry-assisted respiratory training, but not cognitive training, led to corrections from initially hypocapnic to normocapnic levels. Moderated mediation and temporal analyses suggested that in capnometry-assisted respiratory training, PCO₂ unidirectionally mediated and preceded changes in symptom appraisal and perceived control and was unidirectionally associated with changes in panic symptom severity. In cognitive training, reductions in symptom appraisal were bidirectionally associated with perceived control and panic symptom severity. In addition, perceived control was bidirectionally related to panic symptom severity in both treatment conditions.


CONCLUSIONS
The findings suggest that reductions in panic symptom severity can be achieved through different pathways, consistent with the underlying models.
Meuret
Alicia E
AE
Department of Psychology, Southern Methodist University, 6424 Hilltop Lane, Dallas, TX 72505, USA. ameuret@smu.edu
Rosenfield
David
D
Seidel
Anke
A
Bhaskara
Lavanya
L
Hofmann
Stefan G
SG
D000328:Adult; D000379:Agoraphobia / Q000097:blood / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D001008:Anxiety Disorders / Q000097:blood / Q000175:diagnosis / Q000523:psychology / Q000628:therapy; D001143:Arousal; D001945:Breathing Exercises; D002245:Carbon Dioxide / Q000097:blood*; D003072:Cognition Disorders / Q000097:blood / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D015928:Cognitive Behavioral Therapy; D015897:Comorbidity; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000097:blood / Q000175:diagnosis / Q000523:psychology / Q000628:therapy; D016584:Panic Disorder / Q000097:blood / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D056152:Respiratory Rate; D055815:Young Adult
D002245:Carbon Dioxide