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Completed

NCT Number: NCT03925987

Predicting Treatment Response to Exposure Therapy Using Carbon Dioxide

Anxiety disorders affect over a quarter of the population, yet very little is known about the variables that predict treatment outcome. The planned study explores whether a patient's response to a physiological test involving inhalation of carbon dioxide predicts their response to exposure therapy.

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Key information

Conditions

Generalized Anxiety Disorder Agoraphobia Anxiety Disorders Mental Disorders Panic Disorder Phobia, Social Phobic Disorders Social Anxiety Disorder

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Laureate Institute for Brain Research

Tulsa, Oklahoma, 74136, United States

About this study

Anxiety Sensitivity (AS) refers to an individual's fear of experiencing anxiety-related symptoms (e.g., dyspnea or heart palpitations) and is a core construct underlying the initiation and maintenance of pathological anxiety. Recent evidence suggests that reducing AS may be critical for the prevention and treatment of anxiety across diagnostic categories. Exposure therapy, an important component of cognitive behavioral therapy (CBT), is one of the most effective treatments for reducing AS, and has been shown to improve symptoms across a number of different anxiety disorders. Meta-analyses reveal an approximately 50% treatment response rate, with the remaining half of patients showing either no response or dropping out of treatment early. Unfortunately, there is a paucity of research exploring which variables predict treatment outcome and there are currently no tests for predicting which patients would benefit the most from exposure therapy. In this study, participants will complete two sessions of a carbon dioxide (CO2) habituation paradigm, a safe and noninvasive physiological test that entails repeated exposures to single vital capacity inhalations of 20% CO2. Both CO2 testing sessions will be completed within a 72-hour time period. Patients then complete a 10-week group-based exposure therapy to determine whether an individual's degree of habituation to CO2 predicts treatment outcome.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • DSM-V diagnosis of an Anxiety disorder (Generalized Anxiety Disorder, Social Anxiety Disorder, Panic Disorder, Agoraphobia)
  • Anxiety Sensitivity Index (ASI-3) total score > 29
  • Overall Anxiety Severity and Impairment Scale (OASIS) score > 8
  • Between 18-55 years of age
  • Subject must be "treatment-seeking" and willing to enroll in the 10-week group-based Exposure Therapy

Exclusion criteria

  • Comorbid Bipolar Disorder, Schizophrenia, Anorexia or Bulimia Nervosa, or Obsessive-Compulsive Disorder
  • Current Substance Use Disorder > moderate (within the past 6 months)
  • Currently taking a psychotropic medication
  • Currently receiving psychotherapy/counseling for anxiety
  • Currently being treated as an inpatient
  • Active suicidal ideation with intent or plan
  • History of neurological, cardiovascular or respiratory problems (e.g., asthma, severe brain injury)

Treatment and study plan

Exposure Therapy

Behavioral

10 weekly sessions of group-based exposure therapy

Primary outcomes

  1. Between-session habituation of self-reported anxiety

    Time frame: Across two days of CO2 testing within a 72-hour window

    Maximum anxiety rating on a 10-point rating dial (0=no anxiety to 10=most anxiety ever) during day 1 of CO2 testing minus the maximum anxiety rating during day 2 of CO2 testing

Secondary outcomes

  1. Between-session habituation of self-reported dyspnea

    Time frame: Across two days of CO2 testing within a 72-hour window

    Dyspnea rating (difficulty breathing, shortness of breath or smothering) on a 100-point visual analogue scale (0=not at all to 100=extremely) during day 1 of CO2 testing minus the dyspnea rating during day 2 of CO2 testing

  2. Between-session reduction in avoidance behavior

    Time frame: Across two days of CO2 testing within a 72-hour window

    Average response latency (in seconds) between vital capacity breaths of CO2 during day 1 of CO2 testing minus the average response latency during day 2 of CO2 testing

Sponsors and collaborators

Lead sponsor

Laureate Institute for Brain Research, Inc.

Other

Registry information

Official study title

Predicting Treatment Response to Exposure Therapy Using a CO2 Habituation Paradigm in Patients With High Levels of Anxiety Sensitivity

Important dates

Study start
2018
Primary completion
2020
Study completion
2020
First posted
Apr 24, 2019
Registry last updated
Dec 15, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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