Evaluating CO2 Reactivity to Predict Response to Exposure Therapy for Anxiety Disorders

Carbon Dioxide (CO2) Reactivity as a Biomarker of Non-Response to Exposure-Based Therapy

This study is testing whether measuring how people react to CO2 can help predict if adults with anxiety disorders will benefit from exposure therapy.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 600 (estimated)
• Ages: 18 Years to 70 Years
• Sex: All
• Sponsor: University of Texas at Austin (Academic / other)
• Locations: 2 sites (Boston, Massachusetts and 1 other locations)
• Trial ID: NCT05467683 on ClinicalTrials.gov

What this trial studies

This study aims to assess the predictive power of a CO2 challenge as a biomarker for determining the effectiveness of exposure-based therapy in adults with anxiety-related disorders. By evaluating CO2 reactivity in 600 participants diagnosed with conditions such as PTSD, OCD, and various anxiety disorders, the researchers hope to identify those who are likely to benefit from this therapy. The study will incorporate CO2 reactivity into a multivariable model alongside other factors to enhance treatment decision-making. This approach builds on previous research linking orexin system activity to fear extinction deficits.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 to 70 with a primary diagnosis of panic disorder, social anxiety disorder, generalized anxiety disorder, obsessive-compulsive disorder, or post-traumatic stress disorder.

Not a fit: Patients with a history of bipolar or psychotic disorders, substance use disorders, serious cognitive impairment, or active suicidal ideation may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a valuable tool for clinicians to better select patients who will respond to exposure-based therapy, potentially reducing suffering and improving treatment outcomes.

How similar studies have performed: While the approach of using CO2 reactivity as a biomarker is innovative, similar studies have shown promise in linking physiological responses to treatment outcomes, suggesting potential for success.

Eligibility criteria

Inclusion Criteria:

* A primary DSM-5 diagnosis of panic disorder (with or without an agoraphobia diagnosis), social anxiety disorder, generalized anxiety disorder, obsessive-compulsive disorder, or post-traumatic stress disorder as assessed by the Structured Clinical Interview for the DSM-5 (SCID-5)
* A score of 8 or greater on the Overall Anxiety Severity and Impairment Scale (OASIS)
* Ages 18 to 70
* Willingness and ability to provide informed consent and comply with the requirements of the study protocol.
* Proficiency in English (because assessment instruments have only been validated in English)

Exclusion Criteria:

* A lifetime history of bipolar or psychotic disorders, substance use disorders (other than nicotine) or eating disorder in the past 6 months; serious cognitive impairment.
* Active suicidal ideation with at least some intent to act with or without specific plan (a rating of 4 for suicidal ideation on the Columbia-Suicide Severity Rating Scale) or suicidal behaviors (actual attempt, interrupted attempt, aborted or self-interrupted attempt, or preparatory acts or behavior) within the past 6 months.
* Medical conditions contraindicating CO2 inhalation or hyperventilation challenge (e.g., cardiac arrhythmia, cardiac failure, asthma, lung fibrosis, high blood pressure, epilepsy, or stroke).
* Pregnancy or lactation
* Ongoing psychotherapy directed toward the primary disorder.
* Pharmacological treatment started within 8 weeks prior to the screen (patients "stable" on their medication regimen will be included and their medication status will be included as a variable in the model)

Where this trial is running

Boston, Massachusetts and 1 other locations

• Boston University — Boston, Massachusetts, United States (Recruiting)
• The University of Texas at Austin — Austin, Texas, United States (Recruiting)

Study contacts

• Principal investigator: Jasper Smits, Ph.D. — The University of Texas at Austin

Conditions Obsessive-Compulsive Disorder; Post Traumatic Stress Disorder; Generalized Anxiety Disorder; Social Anxiety Disorder; Panic Disorder