Mechanisms of Treatment Change in Panic Disorder and Agoraphobia
Condition: Panic Disorder With Agoraphobia
MeSH terms: Panic Disorder; Agoraphobia
Study type: Interventional

Summary: 
      The primary goal of the present study is to identify mechanisms of therapeutic change of two
      theoretically contrasting therapeutic procedures: The first phase consists of comparing the
      outcome of the capnometry-assisted breathing therapy (BRT) with cognitive restructuring (CT).
      During the second phase participants of both interventions will undergo in-vivo exposure.
    

Detailed description: 
      The primary goal of the present study is to identify mechanisms of therapeutic change of two
      theoretically contrasting therapeutic procedures: While the rationale of breathing training
      is based on the assumption that hypocapnea (lower than normal levels of pCO2) is responsible
      for the development and maintenance of panic disorder, the rationale of cognitive
      interventions is that the primary mechanism in PD is the cognitive misinterpretation of
      benign bodily sensations. Further, while breathing training should induce a low-anxiety state
      (through parasympathetic activation) and, therefore, facilitate habituation to fearful
      situations, voluntary increases in arousal through hyperventilation (sympathetic activation)
      has been suggested to facilitate cognitive restructuring during exposure.

      In order to study mechanisms that potentially produce clinical improvement, the investigators
      propose a 2-phase therapeutic intervention: The first phase consists of comparing the outcome
      of the capnometry-assisted respiratory training (CART) with cognitive restructuring (CT).
      During the second phase participants of both interventions will undergo in-vivo exposure
      therapy.

      With the data collected from the study, the investigators will test the following hypotheses:
      (a) CART will produce more reduction in psycho-physiologically relevant measures of panic
      symptoms compared to CT, while cognitive restructuring will produce more reduction in
      cognitive parameters of panic symptoms; (b) CART will influence the response to voluntary
      hyperventilation tests by leading to faster recovery compared to CT. Improvement in
      respiratory psychophysiology will be correlated with improvement in panic symptom severity;
      (c) Breathing techniques during exposure will lead to a lower-anxiety state, facilitating but
      not inhibiting fear extinction as suggested by the safety aid theory
    

Intervention name(s): Cognitive Therapy; Capnometry-Assisted Respiratory Training; In-vivo exposure
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): The training included four components: (a) educating patients about exacerbating panic symptoms through catastrophic thoughts (vicious cycle), (b) identifying negative cognitions associated with physical sensation triggers of recent panic attacks, (c) practicing replacement of maladaptive cognitions with non catastrophic explanations, and (d) instructing patients in between session exercises during Phase I.; The training included four components: (a) educating patients about the exacerbation of panic symptoms through hypocapnia; (b) directing patients' attention to potentially detrimental respiratory patterns; (c) teaching patients techniques to control their respiration, in particular end-tidal PCO2; and (d) instructing patients in between-session exercises. Between-session exercises using a portable capnometer were to be performed twice a day for 17 min at home or elsewhere during Phase I.; In this two-phase intervention, patients were randomized (within each site) to first receive five individual, weekly, 1-hr sessions of respiratory skill training (CART) or cognitive skill training (CT; Phase I, Skill Acquisition Training), followed by three weekly sessions of in-vivo exposure (Phase II, Application Training) plus a fourth session at 2-month follow-up.
Other intervention name(s): CT; CART; EXP
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Respiration panic; Cognitions; Panic; Treatment; Mediators; Moderators