Methods for Managing Intrusive Thoughts

Study Overview
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Brief Summary
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The current study sought to translate laboratory research on learning and memory to better understand the mechanisms and methods for implementing exposure therapy for unwanted obsessional thoughts. Specifically, we compared the processes and the short- and long-term outcomes of: (a) gradual exposure (EXP-G), emphasizing hierarchical exposure completion, versus (b) variable exposure (EXP-V), emphasizing variability in exposure intensity.

Detailed Description
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Although preliminary research suggests that learning to tolerate varying levels of fear during exposure enhances outcomes for some anxiety-related problems, no previous study has examined this possibility in the context of unwanted obsessions. Adults with a moderately distressing obsessional thought were randomly assigned to four twice-weekly sessions of either: (a) gradual exposure (EXP-G), emphasizing hierarchical exposure completion, or (b) variable exposure (EXP-V), emphasizing variability in exposure intensity.

Official Title
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A Translational Study of the Mechanisms of Exposure Therapy for Obsessions: Gradual vs. Variable Exposure Intensity

Conditions
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Obsessive-Compulsive Disorder

Intervention / Treatment
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* Behavioral: Gradual Exposure (EXP-G)
* Behavioral: Variable Exposure (EXP-V)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least 18 years old Willing to attend and audiotape all study sessions Fluent in English Presence of one or more obsessional thoughts that cause marked distress If on a psychiatric medication (e.g., SSRI), willing to remain at a fixed dose while participating in the study (and stabilized on medication for 30 days before beginning the intervention). Exclusion Criteria: Previous cognitive behavioral therapy (CBT) for anxiety Current suicidal ideation Current substance use disorder Current mania or psychosis Currently taking an anxiolytic (e.g., Ativan) or stimulant (e.g., Ritalin) medication Heart, respiratory, or neurological condition Current pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants were randomly assigned to either gradual or variable exposure
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Gradual Exposure Group<br>The gradual exposure group received the Gradual Exposure (EXP-G) Intervention. | Behavioral: Gradual Exposure (EXP-G)<br>* In EXP-G, exposure proceeded hierarchically from mildly, to moderately, to highly intense stimuli so that exposure intensity gradually built between (but not within) sessions.<br>|
| Experimental: Variable Exposure Group<br>The variable exposure group received the Variable Exposure (EXP-V) Intervention. | Behavioral: Variable Exposure (EXP-V)<br>* In EXP-V, exposure stimuli were chosen at random (i.e., pieces of paper with exposure stimuli written on them were pulled randomly from an opaque container) so that mild, moderate, and high intensity exposures could occur in any order during any of the sessions (the participant was not informed which level was coming next). This aimed to maximize (a) uncertainty, (b) variability in exposure intensity, and (c) variability in corresponding physiological arousal.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score at 3-month follow-up (week 14) | The Y-BOCS is a clinician-administered interview that assesses obsessive compulsive disorder (OCD) symptom severity over the past week. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and 3-month follow-up (week 14) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score at post-treatment (week 2) | The Y-BOCS is a clinician-administered interview that assesses obsessive compulsive disorder (OCD) symptom severity over the past week. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and post-treatment (week 2) | 
| Changes from baseline in Dimensional Obsessive-Compulsive Scale-Unacceptable Thoughts (DOCS-UT) at 3-month follow-up (week 14) | The DOCS-UT is a self-report measure of the clinical severity of the unwanted thoughts (UT) OCD symptom dimension. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and 3-month follow-up (week 14) | 
| Changes from baseline in Dimensional Obsessive-Compulsive Scale-Unacceptable Thoughts (DOCS-UT) at post-treatment (week 2) | The DOCS-UT is a self-report measure of the clinical severity of the unwanted thoughts (UT) OCD symptom dimension. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and post-treatment (week 2) | 
| Changes from baseline in Behavioral Approach Test (BAT) Mean Subjective Units of Distress (SUDS) at 3-month follow-up (week 14) | The BAT is an in vivo measure of participants' behavioral responses to their target obsession. Participant SUDS were collected for 5 increasingly difficult steps participants completed related to their obsessional thought. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and 3-month follow-up (week 14) | 
| Changes from baseline in Behavioral Approach Test (BAT) Mean Subjective Units of Distress (SUDS) at post-treatment (week 2) | The BAT is an in vivo measure of participants' behavioral responses to their target obsession. Participant SUDS were collected for 5 increasingly difficult steps participants completed related to their obsessional thought. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and post-treatment (week 2) | 
| Changes from baseline in Behavioral Approach Test (BAT) Number of Steps Completed at 3-month follow-up (week 14) | The BAT is an in vivo measure of participants' responses to their target obsession. The number of steps participants were able to complete without performing a ritual were calculated. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and 3-month follow-up (week 14) | 
| Changes from baseline in Behavioral Approach Test (BAT) Number of Steps Completed at post-treatment (week 2) | The BAT is an in vivo measure of participants' responses to their target obsession. The number of steps participants were able to complete without performing a ritual were calculated. This measure will be used to assess change over the course of the intervention at four time-points throughout the study (over approximately 3.5 months total). | Baseline (week 0) and post-treatment (week 2) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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OCD