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Clinical Trial Details — Status: Completed

Administrative data

NCT number NCT03628105
Other study ID # REB 2018-161
Secondary ID
Status Completed
Phase N/A
First received
Last updated
Start date August 23, 2018
Est. completion date November 15, 2019

Study information

Verified date December 2019
Source Ryerson University
Contact n/a
Is FDA regulated No
Health authority
Study type Interventional

Clinical Trial Summary

Whether used alone or in combination with other approaches, strategies such as cognitive restructuring (CR) and exposure are well-established treatments for anxiety. CR involves identifying and challenging thoughts, beliefs, or assumptions that maintain anxiety, and exposure involves confronting feared situations, typically in a gradual manner. Many theories have been proposed to explain why exposure is effective. One theory posits that corrective learning occurs only when expectations about the outcome of a situation are violated. Therefore, exposure is thought to be effective when the discrepancy between the expected and actual outcome is maximized. One group of researches has suggested that engaging in CR prior to exposure will prematurely reduce the discrepancy between expectancy and outcome, resulting in less inhibitory learning. As such, they recommend that CR only be conducted after exposure in order to consolidate learning about expectancy violation. This recommendation has not been experimentally studied and is in contrast to what is typically practiced clinically. CR is often introduced in therapy prior to exposure. The present study will determine whether conducting CR before exposure results in (1) greater initial reductions in expectation following CR before exposure, (2) less expectancy violation, and (3) poorer treatment gains at posttreatment and 1-month followup. Eighty-two participants with claustrophobia will be randomly assigned to receive either CR before exposure or CR after exposure. The intervention will be conducted in a single session.


Description:

Inhibitory learning is the extinction of a behavioral response through repeated presentations of a conditioned stimulus (CS) in the absence of an unconditioned stimulus (US, CS-noUS). The CS first elicits a behavioral response through excitatory learning - repeated pairing with the US that naturally elicits the same behavioral response (CS-US). One way that inhibitory learning can be maximized in exposure is by violating one's expectancy about CS-US relationship, such that the individual is surprised by the outcome (e.g., CS-noUS). The purpose of the present study is to evaluate the recommendation to avoid cognitive interventions before exposure. Specifically, the aim is to discover whether cognitive interventions before exposure prematurely reduce expected feared outcome ratings, leading to smaller expectancy violation and poorer inhibitory learning (i.e., exposure session or intervention gains) compared to conducting exposures with a consolidation period following exposure.


Recruitment information / eligibility

Status Completed
Enrollment 97
Est. completion date November 15, 2019
Est. primary completion date November 15, 2019
Accepts healthy volunteers No
Gender All
Age group 17 Years to 65 Years
Eligibility Inclusion Criteria:

1. Self-reported proficiency in English language.

2. High claustrophobic fear as demonstrated by:

1. Self-report of moderate anxiety (score of at least 2 out of 4) if participant had to lie down in small dark chamber without windows for several minutes.

2. Endorsement of claustrophobia according to the DSM-5 criteria for Specific Phobia, with or without Criterion F.

3. Exiting of wooden claustrophobic chamber before 2 minutes have passed, or self-reported fear rating at or exceeding 50/100 fear while in the chamber.

Exclusion Criteria:

1. Current or past cognitive behavioral therapy (i.e., cognitive therapy, exposure) for claustrophobia or anxiety and related disorders in the past year

2. Change in dose of psychotropic medication in the past 3 months.

3. Use of benzodiazepine more frequently than once per week in the past 3 months.

4. Diagnosis of current (past month) panic disorder or agoraphobia.

5. Claustrophobia due to or worsened by current (past month) posttraumatic stress disorder (PTSD).

6. Participants with current (past month) diagnosis of severe depression, bipolar disorder, alcohol/substance use, or psychosis.

7. Presence of imminent suicidality or homicidality.

8. Self-reported medical condition that may make it dangerous for participant to experience heightened emotions or arousal (e.g., heart condition/disease, respiratory problem, asthma triggered by intense emotion/arousal).

9. Participation in professional treatment for claustrophobia between the end of the first lab meeting and the 1-month follow-up (Note: This does not include self-help exposure practice).

10. Weight or height exceeding maximum capacity of claustrophobic chamber (e.g., weight over 250 lbs, height over 6 feet 5 inches).

Study Design


Related Conditions & MeSH terms

  • CR After:Engaging in Cognitive Intervention After Exposure
  • CR Before:Engaging in Cognitive Intervention Before Exposure
  • Phobic Disorders

Intervention

Behavioral:
CR Before Exposure
Participants complete 15 minutes of CR (Preparation) using the "evidence technique" outlined in the cognitive-behavioral manual Mind Over Mood (Greenberger & Padesky, 2016). This technique involves evaluating the validity of expected feared outcomes. Next, participants complete six 5-minute exposure trials using a claustrophobic chamber and other materials (e.g., scarf, mask, handcuffs). Finally, participants complete the 15-minute self-report filler task (including questions from the MMPI-2, Butcher et al., 1989) which acts as a no-treatment comparison to CR being conducted after exposure in the other arm of the study.
CR After Exposure
Participants complete the 15-minute self-report filler task (including questions from the MMPI-2, Butcher et al., 1989) which acts as a no-treatment comparison to CR being conducted before exposure in the other arm of the study. Next, participants complete six 5-minute exposure trials using a claustrophobic chamber and other materials (e.g., scarf, mask, handcuffs). Then, participants complete 15 minutes of CR (Consolidation, Craske et al.'s, 2014) by calculating the difference between predicted and actual expected feared outcomes, and identifying identify (1) whether they believe their feared outcomes occurred (Yes/No), (2) describe how they know this to be true, and (3) reflect on what they learned about their feared outcome or expectancy through exposure.

Locations

Country Name City State
Canada Ryerson University Toronto Ontario

Sponsors (1)

Lead Sponsor Collaborator
Kirstyn L. Krause

Country where clinical trial is conducted

Canada, 

References & Publications (3)

Craske MG, Kircanski K, Zelikowsky M, Mystkowski J, Chowdhury N, Baker A. Optimizing inhibitory learning during exposure therapy. Behav Res Ther. 2008 Jan;46(1):5-27. Epub 2007 Oct 7. Review. — View Citation

Craske MG, Treanor M, Conway CC, Zbozinek T, Vervliet B. Maximizing exposure therapy: an inhibitory learning approach. Behav Res Ther. 2014 Jul;58:10-23. doi: 10.1016/j.brat.2014.04.006. Epub 2014 May 9. — View Citation

Deacon BJ, Sy JT, Lickel JJ, Nelson EA. Does the judicious use of safety behaviors improve the efficacy and acceptability of exposure therapy for claustrophobic fear? J Behav Ther Exp Psychiatry. 2010 Mar;41(1):71-80. doi: 10.1016/j.jbtep.2009.10.004. Epub 2009 Oct 24. — View Citation

Outcome

Type Measure Description Time frame Safety issue
Other Self-reported depression, anxiety, and stress as measured by the Depression Anxiety Stress Scales (21-item version) Self-report questionnaire measuring emotional states of depression, anxiety, and stress in the past week. Each subscale contains 7 items, which are first summed, then doubled. Scores on each subscale can range from 0 to 42, with greater scores indicating greater levels of distress Administered once on day 1 at pretreatment.
Other Treatment expectancy and credibility as measured by the Credibility/Expectancy Questionnaire Self-report measure assessing the perceived credibility and expectancy of exposure therapy. Answers to each of the 6 items are transformed into standard scores and summed to create either a total score, or a subscale credibility score or treatment expectancy score. The range of scores is not exact given that standard scores indicate deviations from the mean. According to the normal distribution, approximately 99.7% of participants should fall within a score -3 and +3 for each item, yielding a likely total range between -15 and +15 for the total score and -9 and +9 for each subscale score (credibility, treatment expectancy). Greater scores indicating greater treatment expectancy and credibility ratings. Administered once on day 1 during the intervention.
Other Perceived Actual Outcome: Personal Verbal self-report measure used to evaluate how strongly the participant believes their Expected Feared Outcome: Personal actually occurred during the previous claustrophobic exposure trial on a scale from 0% (Not at all) to 100% (Completely). Administered six times on day 1 (during the intervention) and one time at 1-month follow-up.
Other Perceived Actual Outcome: Suffocation Verbal self-report measure used to evaluate how strongly the participant believes their Expected Feared Outcome: Suffocation actually occurred during the previous claustrophobic exposure trial on a scale from 0% (Not at all) to 100% (Completely). Administered six times on day 1 (during the intervention) and one time at 1-month follow-up.
Other Perceived Actual Outcome: Restriction Verbal self-report measure used to evaluate how strongly the participant believes their Expected Feared Outcome: Restriction actually occurred during the previous claustrophobic exposure trial on a scale from 0% (Not at all) to 100% (Completely). Administered six times on day 1 (during the intervention) and one time at 1-month follow-up.
Other Expectancy Violation: Personal Change score calculated by subtracting the Perceived Actual Outcome: Personal rating (see "Other Pre-specified Outcome Measures" for definition) after each exposure trial from the Expected Feared Outcome: Personal rating before each exposure trial. Scores can range between 0% and 100% with greater scores indicating greater Expectancy Violation: Personal. Change score calculated using expected feared outcome and perceived actual outcome ratings completed 6 times (for each of the 6 exposure trials) on day 1 during the intervention.
Other Expectancy Violation: Suffocation Change score calculated by subtracting the Perceived Actual Outcome: Suffocation rating (see "Other Pre-specified Outcome Measures" for definition) after each exposure trial from the Expected Feared Outcome: Suffocation rating before each exposure trial. Scores can range between 0% and 100% with greater scores indicating greater Expectancy Violation: Suffocation. Change score calculated using expected feared outcome and perceived actual outcome ratings completed 6 times (for each of the 6 exposure trials) on day 1 during the intervention.
Other Expectancy Violation: Restriction Change score calculated by subtracting the Perceived Actual Outcome: Restriction rating (see "Other Pre-specified Outcome Measures" for definition) after each exposure trial from the Expected Feared Outcome: Restriction rating before each exposure trial. Scores can range between 0% and 100% with greater scores indicating greater Mean Expectancy Violation: Suffocation. Change score calculated using expected feared outcome and perceived actual outcome ratings completed 6 times (for each of the 6 exposure trials) on day 1 during the intervention.
Primary Change from pretreatment (i.e., baseline) Behavioral Approach Test (BAT): Behavioral Approach at posttreatment and 1-month follow-up The BAT includes eight 30-second cumulative steps designed to elicit increasing fear of suffocation and restriction (e.g., sleeping bag, mask, hand-cuffs, blankets), and is adapted from Deacon et al. (2010). An index of behavioral approach will be calculated by summing the number of points accrued in each step. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Primary Change from pretreatment (i.e., baseline) Behavioral Approach Test (BAT): Peak Fear at posttreatment and 1-month follow-up Self-report measure assessing the highest level of fear experienced during the final completed step of the BAT at pretreatment from 0% (No Fear) to 100% (Extreme fear). Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Primary Change from pretreatment (i.e., baseline) self-reported claustrophobic anxiety as measured by Claustrophobia Questionnaire: Total score at posttreatment and 1-month follow-up Self-report measure assessing the severity of claustrophobic anxiety in situations eliciting fear of suffocation and restriction. 26 items are summed to create a total score. Total scores range from 0 to 104 with higher scores indicating greater claustrophobic anxiety. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Behavioral Approach Test (BAT): Urge to Escape Self-report measure assessing the strongest urge to escape experienced during the final completed step of the BAT at pretreatment from 0% (No Urge to Escape) to 100% (Extreme Urge to Escape). Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Self-reported Suffocation Anxiety as measured by the Claustrophobia Questionnaire: Suffocation subscale Subscale self-report measure assessing the severity of claustrophobic anxiety in situations eliciting fear of suffocation. Fourteen items are summed to create a subscale score. Scores range from 0 to 56 with greater scores indicating greater suffocation anxiety. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Self-reported Restriction Anxiety as measured by the Claustrophobia Questionnaire: Restriction subscale Subscale self-report measure assessing the severity of claustrophobic anxiety in situations eliciting fear of restriction. Twelve items are summed to create a subscale score. Scores range from 0 to 48 with greater scores indicating greater restriction anxiety. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Self-reported Fear of Suffocation as measured by the Claustrophobia General Cognitions Questionnaire: Suffocation subscale Subscale self-report measure of the likelihood of claustrophobic cognitions about suffocation while in enclosed spaces. Eight items are summed to create a subscale score. Scores range from 0 to 40 with greater scores indicating greater fear of suffocation. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Self-reported Fear of Inability to Escape as measured by the Claustrophobia General Cognitions Questionnaire: Inability to Escape subscale Subscale self-report measure of the likelihood of claustrophobic cognitions about inability to escape while in enclosed spaces. Eight items are summed to create a subscale score. Scores range from 0 to 40 with greater scores indicating greater fear of inability to escape. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Self-reported Fear of Loss of Control as measured by the Claustrophobia General Cognitions Questionnaire: Loss of control subscale Subscale self-report measure of the likelihood of claustrophobic cognitions about loss of control while in enclosed spaces. Nine items are summed to create a subscale scores. Scores range from 0 to 45 with greater scores indicating greater fear of loss of control. Administered before the intervention on day 1 (pretreatment), immediately after the intervention on day 1 (posttreatment, same day as pretreatment) and at 1-month follow-up.
Secondary Expected Feared Outcome: Personal Verbal self-report measure evaluating the extent to which the participant believes his or her personal expected feared (selected from the CGCQ) would occur in a frightening claustrophobic exposure exercise for a specified duration on a scale from 0% (Not at all) to 100% (Completely). Administered eight times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Expected Feared Outcome: Suffocation Verbal self-report measure used to evaluate the extent to which the participant believes he or she will suffocate when in a frightening claustrophobic exposure exercise for a specified duration on a scale from 0% (Not at all) to 100% (Completely). Administered eight times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Expected Feared Outcome: Restriction Verbal self-report measure used to evaluate the extent to which the participant believes he or she will become trapped when in a frightening claustrophobic exposure exercise for a specified duration on a scale from 0% (Not at all) to 100% (Completely). Administered eight times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Expected Feared Outcome: Peak Fear Verbal self-report measure used to evaluate the highest amount of fear participants believe they will experience in a frightening claustrophobic exposure exercise for a specified duration on a scale from 0% (No Fear) to 100% (Extreme Fear). Administered eight times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Expected Feared Outcome: Urge to Escape Verbal self-report measure used to evaluate the strongest urge to escape participants believe they will experience in a frightening claustrophobic exposure exercise for a specified duration on a scale from 0% (No Urge to Escape) to 100% (Extreme Urge to Escape). Administered eight times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Perceived Actual Outcome: Peak Fear The highest level of fear the participant experienced during the previous claustrophobic exposure trial on a scale from 0% (No Fear) to 100% (Extreme fear). Administered six times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Perceived Actual Outcome: Urge to Escape The strongest urge to escape the participant experienced during the previous claustrophobic exposure trial on a scale from 0% (No urge to escape) to 100% (Extreme urge to escape). Administered six times on day 1 (during the intervention) and one time at 1-month follow-up.
Secondary Mean Expectancy Violation: Personal The mean of the 6 change scores calculated for Expectancy Violation: Personal (i.e., the difference between the Perceived Actual Outcome: Personal rating after each exposure trial from the Expected Feared Outcome: Personal rating before each exposure trial - see Other pre-specified outcomes). Scores can range between 0% and 100% with greater scores indicating greater Mean Expectancy Violation: Personal. Mean of 6 Expectancy Violation: Personal change scores calculated on day 1 during the intervention.
Secondary Mean Expectancy Violation: Suffocation The mean of the 6 change scores calculated for Expectancy Violation: Suffocation (i.e., the difference between the Perceived Actual Outcome: Suffocation rating after each exposure trial from the Expected Feared Outcome: Suffocation rating before each exposure trial - see Other pre-specified outcomes). Scores can range between 0% and 100% with greater scores indicating greater Mean Expectancy Violation: Suffocation. Mean of 6 Expectancy Violation: Suffocation change scores calculated on day 1 during the intervention.
Secondary Mean Expectancy Violation: Restriction The mean of the 6 change scores calculated for Expectancy Violation: Restriction (i.e., the difference between the Perceived Actual Outcome: Restriction rating after each exposure trial from the Expected Feared Outcome: Restriction rating before each exposure trial - see Other pre-specified outcomes). Scores can range between 0% and 100% with greater scores indicating greater Mean Expectancy Violation: Restriction. Mean of 6 Expectancy Violation: Restriction change scores calculated on day 1 during the intervention.