CO2 reactivity as a biomarker of exposure-based therapy non-response: study protocol.
Jasper A J Smits, Marie-H Monfils, Michael W Otto...
https://pubmed.ncbi.nlm.nih.gov/36575425Actively Recruiting
Phase Not Applicable
Age: 18Years - 70Years
All Genders
ID05467683
Carbon Dioxide (CO2) Reactivity as a Biomarker of Non-Response to Exposure-Based Therapy for Anxiety and Related Disorders
Led by University of Texas at Austin · Updated on 2026-02-19
600
Participants Needed
2
Research Sites
12 weeks
Total Duration
On this page
Sponsors
U
University of Texas at Austin
Lead Sponsor
B
Boston University
Collaborating Sponsor
AI-Summary
What this Trial Is About
Anxiety, obsessive-compulsive, trauma, and stressor-related disorders are significant public health concerns. Researchers are evaluating whether a new biomarker based on a carbon dioxide (CO2) challenge can help predict non-response to exposure-based therapy, a common treatment for these conditions. This study aims to determine if this easy-to-administer test can assist clinicians in deciding whether to start exposure-based therapy for patients with these disorders. The study involves 600 adults aged 18 to 70 diagnosed with one or more fear- or anxiety-related disorders. All participants will receive 12 weekly one-hour sessions of exposure-based therapy delivered by trained clinicians. The therapy is personalized to help patients safely face feared situations and learn that their fears do not come true. The study will measure CO2 reactivity, along with other factors, before treatment to build models predicting who may not respond to therapy. Participants will be assessed weekly for 14 weeks and followed up after 24 weeks using various clinical scales for anxiety and related symptoms. Researchers will monitor treatment response and non-response at week 13, using these outcome measures. The study also includes careful monitoring for safety, and participants will receive the therapy openly without placebo control. The total involvement includes assessments before, during, and after the treatment period.
CONDITIONS
Brief Title
CO2 Reactivity as a Biomarker of Non-Response to Exposure-Based Therapy
Who Can Participate
Age: 18Years - 70Years
All Genders
Eligibility Criteria
You may qualify if you...
- Adults aged 18 to 70 years
- Primary DSM-5 diagnosis of panic disorder, social anxiety disorder, generalized anxiety disorder, obsessive-compulsive disorder, or post-traumatic stress disorder confirmed by clinical interview
- Score of 8 or greater on the Overall Anxiety Severity and Impairment Scale (OASIS)
- Willing and able to provide informed consent and follow study procedures
- Proficient in English as assessments are validated only in English
You will not qualify if you...
- History of bipolar disorder, psychotic disorders, substance use disorders (except nicotine), or eating disorders in past 6 months
- Active suicidal thoughts with intent or suicidal behaviors within past 6 months
- Medical conditions that prevent CO2 inhalation or hyperventilation challenge such as heart problems, asthma, lung fibrosis, high blood pressure, epilepsy, or stroke
- Pregnant or breastfeeding
- Currently receiving psychotherapy for the primary disorder
- Started new medication for the primary disorder within 8 weeks prior to screening unless stable on medication regimen
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
1
2
3
Your Study Journey
Screening
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Treatment
Duration - 12 weeks
Participants receive 12 weekly one-hour sessions of exposure-based therapy delivered by trained clinicians, focusing on personalized assessment and exposure exercises to help reestablish safety around feared cues.
Weekly visits for up to 12 weeks
Follow-up
Duration - Up to 24 weeks after treatment
Participants are monitored for clinical outcomes weekly during treatment and at a follow-up after 24 weeks to assess treatment response and symptom changes.
Weekly visits for 14 weeks including treatment period and 1 follow-up visit after 24 weeks
Trial Site Locations
Total: 2 locations
1
Boston University
Boston, Massachusetts, United States, 02215
Actively Recruiting
2
The University of Texas at Austin
Austin, Texas, United States, 78712
Actively Recruiting
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How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
TREATMENT
Number of Arms
1
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