Recruiting

Observational Study

Sponsor:

Jasper A. Smits

Code:

NCT05467683

Conditions

Obsessive-Compulsive Disorder

Post Traumatic Stress Disorder

Generalized Anxiety Disorder

Social Anxiety Disorder

Panic Disorder

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Interventions

Exposure-Based Therapy

Study Details

Brief summary:

Anxiety-, obsessive-compulsive and trauma- and stressor-related disorders reflect a significant public health problem. This study is designed to evaluate the predictive power of a novel biomarker based on a CO2 challenge, thus addressing the central question "can this easy-to-administer assay aid clinicians in deciding whether or not to initiate exposure-based therapy?"

Conditions

Obsessive-Compulsive Disorder

Post Traumatic Stress Disorder

Generalized Anxiety Disorder

Social Anxiety Disorder

Panic Disorder

Study ID

NCT05467683

Start date

Nov 2, 2022

Status verified date

Jun, 2026

Completion date

Feb 28, 2027

Anticipated

Primary completion date

Dec 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

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)

Study Design

Enrollment

600 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

other: Open Exposure-Based Therapy (EBT)

All participants will receive a well-established psychological treatment.

Interventions

Exposure-Based Therapy

Treatment will consist of 12 one-hour sessions, delivered over the course of 12 weeks. EBT will be delivered by trained and experienced license-eligible clinicians. The study clinician will develop a personalized assessment and treatment plan for each patient. Consistent with contemporary models of EBT, exposure practice aims to help patients reestablish a sense of safety around feared cues. Hence, exposure exercises are planned to ensure violation of threat expectancies. That is, exposure practice is deemed appropriate and effective if it allows the patient to learn that what they feared would happen does not happen. Practice will occur across relevant contexts both within and outside the session (i.e., homework) and clinicians will guide patients in processing practice to facilitate the consolidation of safety learning. To achieve these ends, study clinicians will use the manual "Personalized Exposure Therapy: A Person-Centered Transdiagnostic Approach".

Primary outcome measure

  • Non-response to exposure-based therapy [ Time Frame: Week 13 (post-treatment) ]

Central Contacts and Locations

Locations

Boston University

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Michael Otto, Ph.D.

617-353-9610mwotto@bu.edu

The University of Texas at Austin

Recruiting

Austin, Texas, United States, 78712

Contacts

Jasper Smits, Ph.D.

512-475-8095smits@utexas.edu

More Information

Sponsor

Jasper A. Smits

Last update posted

Jun 10, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Jasper A. Smits on 2026-06-10.