Respiratory Training in the Treatment of Transdiagnostic Pathological Anxiety

Not Applicable

Recruiting

• Conditions: Posttraumatic Stress Disorder; Panic Disorder; Generalized Anxiety Disorder; Agoraphobia; Acute Stress Disorder; Anxiety Disorders; Illness Anxiety Disorder; Social Anxiety Disorder; Adjustment Disorder With Anxious Mood; Trauma

• Registration Number: NCT05427708
• Lead Sponsor: University of Texas at Austin

Brief Summary

Purpose of the Research: The primary aim of the proposed study is to conduct a randomized parallel-group 2-arm clinical trial investigating capnometry-guided respiratory intervention (CGRI) for pathological anxiety. CGRI aims to raise end-tidal CO2 levels thereby lowering hyperventilation-induced respiratory alkalosis and its associated fear-eliciting somatic reactions. Psycho-education about anxiety and its effects (PsyEd) will serve as a credible control comparator.

Detailed Description

Low end-tidal CO2 (ETCO2), which is an accompanying feature of hyperventilation, has been associated with a variety of anxiety disorders, including panic disorder and social phobia. More recently, researchers have examined the efficacy of capnometry-guided respiratory intervention (CGRI) as a method for increasing ETCO2 and thereby reducing hyperventilation-induced anxiety/panic symptoms. Promising preliminary efficacy studies have shown that CGRI results in decreased panic symptom frequency and severity at a rate comparable to that of cognitive therapy. A recent uncontrolled proof-of-concept study showed that CGRI led to significant reductions in trauma symptoms in a sample of patients meeting DSM-5 criteria for PTSD. However, CGRI has not been adequately evaluated in the treatment of anxiety disorders other than panic disorder with or without agoraphobia.

Study Timeline

• Study First Submitted: 2022-03-01
• Study First Submitted QC: 2022-06-16
• Study First Posted: 2022-06-22
• Study Start: 2022-08-22
• Status Verified: 2025-08
• Last Update Submitted: 2025-08-18
• Last Update Posted: 2025-08-24
• Primary Completion: 2027-05
• Study Completion: 2027-05-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 180

Inclusion Criteria

1. Clinically elevated anxiety as indicated by an eight or higher on the Overall Anxiety Severity and Impairment Scale (OASIS).

2. Meets DSM-5 criteria for one or more of the following anxiety or trauma-related disorders as their "primary" mental disorder:

   • Generalized Anxiety Disorder
   • Panic Disorder
   • Health Anxiety
   • Agoraphobia
   • Social Anxiety Disorder
   • Posttraumatic Stress Disorder
   • Acute Stress Disorder
   • Adjustment Disorder with primary anxious mood
   • Anxiety disorder not otherwise specified

3. No current use of psychotropic medications or stable on current medications for at least 6 weeks

4. Age 18+.

5. Able to arrange transportation to our laboratory for study appointments.

6. Fluent in English.

Exclusion Criteria

1. No history of medical conditions that would contraindicate participation in fear-provocation or respiratory challenges, including:

   • Cardiovascular or respiratory disorders
   • High blood pressure
   • Epilepsy
   • Strokes
   • Seizures
   • History of fainting
   • Pregnant or lactating

2. Not currently receiving other psychological treatment for anxiety.

3. No history of a suicide attempt within the past 6 months.

4. No history of psychosis within the past 6 months.

5. No history of moderate to severe alcohol or substance use disorder (with the exception of nicotine) within the past 3 months.

6. Does not endorse COVID-19 symptoms during the screening phase.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Computerized Hamilton Anxiety Scale	Pre-Treatment (Week 0), Post-treatment (Week 5), 2-Month Follow-Up (Week 13)	Change from baseline in anxiety symptom severity. Each item is assessed both in terms of frequency and severity. Scores on these probes are summed and divided by the number of response options. Higher scores index higher severity.
Overall Anxiety Severity and Impairment Scale	Pre-Treatment (Week 0), Post-treatment (Week 5), 2-Month Follow-Up (Week 13)	Change from baseline in self-reported transdiagnostic anxiety symptoms (range = 0 - 20, with higher scores indexing more symptoms).

Secondary Outcome Measures

Name	Time	Method
Sheehan Disability Scale	Pre-Treatment (Week 0), Weekly Assessments (Weeks 1 - 4), Post-treatment (Week 5), 2-Month Follow-Up (Week 13)	Change from baseline in overall disability (range = 0 - 30, with higher scores indexing more disability).
Anxiety Sensitivity Composite Measure	Pre-Treatment (Week 0), Weekly Assessments (Weeks 1 - 4), Post-treatment (Week 5), 2-Month Follow-Up (Week 13)	This composite measure will incorporate scores on the Anxiety Sensitivity Index-3 (ASI-3), Body Sensations Questionnaire (BSQ), and Texas Multi-Factor Anxiety Sensitivity Scale (TMASS). Scores on each of these individual measures will be transformed into z scores and then averaged to derive this composite index. We will measure change from baseline in anxiety sensitivity.
PROMIS - Global Health (Mental Health Subdomain)	Pre-Treatment (Week 0), Weekly Assessments (Weeks 1 - 4), Post-treatment (Week 5), 2-Month Follow-Up (Week 13)	Change from baseline in quality of life (range = 4 - 20, with higher scores indexing higher quality of life).
Modified DIAMOND	Pre-Treatment (Week 0), 2-Month Follow-Up (Week 13)	Change from baseline in DIAMOND Diagnostic Interview + Health Anxiety Questionnaire scores.

Trial Locations

Locations (1)

University of Texas at Austin; 🇺🇸 Austin, Texas, United States