Mechanisms of Exposure Therapy for OCD

Study Overview
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Brief Summary
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Exposure therapy is the most effective treatment available for obsessive compulsive disorder, yet up to 50% of patients do not recover because the mechanisms underlying successful response are poorly understood, leading to significant variability in how clinicians conduct exposure therapy. The main purpose of this study is to determine which target mechanisms are most critical to engage in real-world exposure sessions to produce good treatment outcomes. Adult participants (N = 400) with Obsessive Compulsive Disorder (OCD) receiving exposure therapy from two sites (McLean Hospital, San Diego State University) across the continuum of care (outpatient, partial hospital, residential) will complete baseline clinical and demographic measures as well as weekly symptom reports. The project will measure exposure mechanisms across three levels of analysis (self-report, observer-rated behavior, physiology) during each exposure session. Mechanisms assessed will include a broad range of variables based on both habituation and inhibitory learning models of exposure. Self-report and observer-rated mechanisms will be measured with the Exposure Feedback Form, created and piloted by the study team. Physiological mechanisms will include skin conductance response, heart rate, and heart rate variability measured with a wristwatch. The current study will determine (1) which exposure mechanisms lead to favorable clinical outcomes, and (2) what makes a good exposure for whom. Results of this study have the potential to improve personalized care for the many patients who do not remit following exposure therapy for OCD.

Official Title
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Leveraging Machine Learning Approaches to Understand Mechanisms of Exposure Therapy in Real-World Settings

Conditions
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Obsessive-Compulsive Disorder

Intervention / Treatment
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* Behavioral: Exposure therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Between the ages of 18-65 years old Seeking exposure treatment at McLean Hospital OCD Institute or San Diego State University Have a diagnosis of OCD Able to complete study measures and treatment procedures in English Exclusion Criteria: Acute symptoms of psychosis Active suicidality (plan, means, intent and/or suicide attempt in past 3 months) Presence of co-occurring symptoms that warrant higher level of care (e.g., inpatient treatment) Presence of any medical, psychiatric, or developmental condition that would prevent patients from completing assessments or exposure exercises (e.g., non-verbal autism spectrum disorder)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exposure therapy<br>Participants will complete exposure therapy for up to 12 weeks, and each coached exposure session will be approximately 50 minutes. Exposure plans will be developed collaboratively between participants and their clinician at the beginning of treatment, and refined iteratively as clinically appropriate. In each coached exposure, participants will: Complete an Exposure Feedback Form Wear a wristwatch that provides psychophysiological data The intervention will occur across two study sites (McLean Hospital, San Diego State University). Sites will differ on level of care. At McLean Hospital, participants will be recruited from the OCD Institute and will receive exposure therapy via partial hospital or residential setting as part of their standard care, regardless of participation in the study. At San Diego State University, participants will be recruited to receive exposure therapy via outpatient setting. | Behavioral: Exposure therapy<br>* Participants will complete exposure therapy for up to 12 weeks, and coached exposure session will be approximately 50 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Yale-Brown Obsessive Compulsive Scale (YBOCS) | The YBOCS is a 10 self-report measure of OCD severity. | Up to 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of Life Enjoyment & Satisfaction Questionnaire (QLES) | The QLES is a 14-item self-report measure assesses the degree of enjoyment and satisfaction experienced in various daily functioning domains. | Up to 12 weeks |