Inference-Based Cognitive Therapy Versus Exposure and Response Prevention for Obsessive-Compulsive Disorder

Study Overview
=================
Brief Summary
-----------------
Obsessive-compulsive disorder (OCD) is a highly disabling psychiatric illness, characterized by obsessional thoughts that cause patients to perform time-consuming and distressing compulsive rituals. Exposure and Response Prevention (ERP) is a first-line psychological treatment of choice, which requires patients to face their fears by being exposed to feared stimuli. ERP has been shown to reduce symptoms among those who comply with treatment. However, there is still a significant portion of patients that do not improve, especially those who firmly believe their obsessions are realistic and reasonable (i.e. OCD with Overvalued Ideation (OVI)). Also, a signficant proportion of patients refuse the treatment or drop out during treatment due to the distress provoked by ERP. Even among those that do improve, residual symptoms often remain, or symptoms may reappear after treatment. One evidence-based approach to the treatment of OCD, termed inference-based cognitive therapy (IBCT) has been shown to be as effective as ERP with the potential to overcome some of the limitations of ERP. Since IBCT is a cognitive approach, the treatment does not require exposure to feared stimuli and likely more tolerable for patients with OCD. Also, there is evidence that IBCT is more effective than ERP for those with overvalued ideation, since it directly targets the distorted reasoning that is responsible for the intensity and persistence of the obsession. The current study aims to directly compare ERP with this promising evidence-based cognitive therapy, which is expected to be significantly more effective for those with overvalued ideation, as well as significantly more tolerable with lower rates of treatment refusal, drop-out and higher treatment satisfaction. The project is designed to maximize potential beneficial health outcomes and offer a new evidence-based treatment option for the large proportion of patients unable to benefit from ERP.

Detailed Description
-----------------
The proposed study is a parallel-group randomized controlled trial developed in accordance with CONSORT quality guidelines.The RCT will compare the outcome of 16 sessions of IBCT compared to 16 sessions of ERP in OCD patients. The principal investigators and independent evaluators will be blind to the random allocation treatment conditions with a randomization ratio of 1:1. Both treatments will be administered by trained therapists on a weekly one-on-one basis over a 16-week period with 6-month follow-up conforming to current thinking on relapse in OCD. Conditions of treatment delivery, duration and monitoring will be equivalent across all groups. Both treatments are manualized and any newly engaged therapists will receive intensive training in one therapy protocol to ensure optimal delivery of each modality. The objective of the present study is to establish IBCT as a psychological treatment that is as effective as ERP, but significantly more tolerable and generalizable for the high proportion of patients who are unable to benefit from ERP. The hypotheses are that 1) IBCT is non-inferior to ERP; 2) IBCT is superior to ERP among OCD patients with higher levels of OVI; 3) IBCT has lower rates of treatment refusal and drop-out than ERP; and, 4) IBCT has higher levels of acceptability, tolerability, credibility and satisfaction than ERP.

Official Title
-----------------
Inference-Based Cognitive Therapy Versus Exposure and Response Prevention for Obsessive-Compulsive Disorder: A 16-Session Randomized Controlled Trial

Conditions
-----------------
Obsessive-compulsive Disorders and Symptoms, Obsessive-Compulsive Disorder

Intervention / Treatment
-----------------
* Behavioral: Exposure and response prevention
* Other: Inference-based cognitive therapy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: a primary diagnosis of OCD according to Diagnostical and Statistical Manual, version 5 criteria; no change in medication during the 12 weeks before treatment for antidepressants (4 weeks for anxiolytics); willingness to keep medication stable while participating in the study; no evidence of suicidal intent; no evidence of current substance abuse; no evidence of current or past schizophrenia, bipolar disorder or organic mental disorder; not undergoing a current psychological treatment; willingness to undergo active psychological treatment; willingness to undergo randomization into treatment modality; fluency in English and French. Exclusion criteria: another primary diagnosis than OCD requiring treatment; medication not stabilized for 12 weeks; medication will change during the participation; suicidal intent.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The RCT will compare the outcome of 16 sessions of IBCT compared to 16 sessions of ERP in OCD patients. The evaluators will be blind to the random allocation treatment conditions with a randomization ratio of 1:1. Both treatments will be administered by trained therapists on a weekly one-on-one basis over a 16-week period with 6-month follow-up conforming to current thinking on relapse in OCD. Conditions of treatment delivery, duration and monitoring will be equivalent across all groups. Both treatments are manualized and therapists will receive intensive training in one therapy protocol to ensure optimal delivery of each modality. Due to COVID-19, as of April, 2020, treatment will be delivered to participants by videoconferencing only. To protect the integrity and internal validity of the trial, participants who were recruited before this date and received the majority of treatment sessions in face-to-face physical meetings will be excluded from the principal statistical analyses.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Inference-based cognitive therapy<br>The treatment primarily targets the dysfunctional reasoning and overvalued ideas. IBCT does not include exposure, but aims to bring resolution to the initial obsessional doubt or overvalued idea by showing the participant that the obsession is the result of incorrect reasoning. | Other: Inference-based cognitive therapy<br>* The treatment primarily targets the dysfunctional reasoning that gives rise to obsessional doubts and overvalued ideas. IBCT does not include exposure in vivo, but instead, aims to bring resolution to the initial obsessional doubt or overvalued idea by showing the participant that the obsession is the result of incorrect reasoning.<br>* Other names: IBCT;|
| Active Comparator: Exposure and response prevention<br>ERP is a treatment developed to help people confront their fears based on the rationale that exposure to feared objects, activities, or situations in a safe environment helps reduce fear and decrease avoidance. During the treatment, patients will engage in these exposures to feared stimuli within and between sessions according to hierarchies developed during the initial evaluation sessions, and refrain from engaging in compulsive behaviour until their anxiety subsides (i.e. ritual prevention). | Behavioral: Exposure and response prevention<br>* ERP is a treatment developed to help people confront their fears based on the rationale that exposure to feared objects, activities, or situations in a safe environment helps reduce fear and decrease avoidance. During the treatment, participants will engage in these exposures to feared stimuli within and between sessions according to hierarchies developed during the initial evaluation sessions, and refrain from engaging in compulsive behaviour until their anxiety subsides (i.e. ritual prevention). Exercises will consist of both exposure in vivo (i.e. exposure in real life situations) and/or imaginal exposure according to recommendations.<br>* Other names: ERP;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| assessment of change in obsessive and compulsive symptoms and severity | The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is a 10-item scale designed to measure the severity and type of symptoms in people with obsessive-compulsive disorder (OCD) over the past seven days. The symptoms assessed are obsessions and compulsions. This scale is useful in tracking OCD symptoms at intake and during/after treatment. Total Y-BOCS scores range from 0 to 40, with higher scores indicating greater severity of OCD symptoms. Scores on the obsession and compulsion subscales range from 0 to 20, but only the total Y-BOCS score is interpreted. Total scores can be split into five categories, based on severity of symptoms. People who have a total Y-BOCS score: Under 7 are likely to be subclinical, 8-15 are likely to have a mild case of OCD, 16-23 are likely to have a moderate case of OCD, 24-31 are likely to have a severe case of OCD, 32-40 are likely to have an extreme case of OCD. | baseline measure of obsessive and compulsive symptoms of OCD | 
| assessment of change in obsessive and compulsive symptoms and severity | The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is a 10-item scale designed to measure the severity and type of symptoms in people with obsessive-compulsive disorder (OCD) over the past seven days. The symptoms assessed are obsessions and compulsions. This scale is useful in tracking OCD symptoms at intake and during/after treatment. Total Y-BOCS scores range from 0 to 40, with higher scores indicating greater severity of OCD symptoms. Scores on the obsession and compulsion subscales range from 0 to 20, but only the total Y-BOCS score is interpreted. Total scores can be split into five categories, based on severity of symptoms. People who have a total Y-BOCS score: Under 7 are likely to be subclinical, 8-15 are likely to have a mild case of OCD, 16-23 are likely to have a moderate case of OCD, 24-31 are likely to have a severe case of OCD, 32-40 are likely to have an extreme case of OCD. | up to 8 weeks | 
| assessment of change in obsessive and compulsive symptoms and severity | The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is a 10-item scale designed to measure the severity and type of symptoms in people with obsessive-compulsive disorder (OCD) over the past seven days. The symptoms assessed are obsessions and compulsions. This scale is useful in tracking OCD symptoms at intake and during/after treatment. Total Y-BOCS scores range from 0 to 40, with higher scores indicating greater severity of OCD symptoms. Scores on the obsession and compulsion subscales range from 0 to 20, but only the total Y-BOCS score is interpreted. Total scores can be split into five categories, based on severity of symptoms. People who have a total Y-BOCS score: Under 7 are likely to be subclinical, 8-15 are likely to have a mild case of OCD, 16-23 are likely to have a moderate case of OCD, 24-31 are likely to have a severe case of OCD, 32-40 are likely to have an extreme case of OCD. | up to 16 weeks | 
| assessment of change in obsessive and compulsive symptoms and severity | The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is a 10-item scale designed to measure the severity and type of symptoms in people with obsessive-compulsive disorder (OCD) over the past seven days. The symptoms assessed are obsessions and compulsions. This scale is useful in tracking OCD symptoms at intake and during/after treatment. Total Y-BOCS scores range from 0 to 40, with higher scores indicating greater severity of OCD symptoms. Scores on the obsession and compulsion subscales range from 0 to 20, but only the total Y-BOCS score is interpreted. Total scores can be split into five categories, based on severity of symptoms. People who have a total Y-BOCS score: Under 7 are likely to be subclinical, 8-15 are likely to have a mild case of OCD, 16-23 are likely to have a moderate case of OCD, 24-31 are likely to have a severe case of OCD, 32-40 are likely to have an extreme case of OCD. | change from baseline at 6 months | 
| establishing baseline level of overvalued ideation | The Over-Valued Ideas Scale (OVIS) is an 11-item clinician administered scale assess severity of overvalued ideation. These include how strong obsessive belief; how reasonable the belief is; how weak and strong the belief has fluctuated over the past week; how accurate the belief is; the extent to which others share the same beliefs; how the patient attributes similar or differing beliefs in other people; how effective and important the compulsions are; the extent to which their disorder has caused their obsessive belief; and their degree of resistance toward the belief on a 1 to 10 scale. The average of the 11 items provides an estimate of one's degree of OVI, where higher scores represent greater levels of OVI. | baseline measure | 
| assess change in level of overvalued ideation | The Over-Valued Ideas Scale (OVIS) is an 11-item clinician administered scale assess severity of overvalued ideation. These include how strong obsessive belief; how reasonable the belief is; how weak and strong the belief has fluctuated over the past week; how accurate the belief is; the extent to which others share the same beliefs; how the patient attributes similar or differing beliefs in other people; how effective and important the compulsions are; the extent to which their disorder has caused their obsessive belief; and their degree of resistance toward the belief on a 1 to 10 scale. The average of the 11 items provides an estimate of one's degree of OVI, where higher scores represent greater levels of OVI. | change from baseline at 8 weeks | 
| assess change in level of overvalued ideation | The Over-Valued Ideas Scale (OVIS) is an 11-item clinician administered scale assess severity of overvalued ideation. These include how strong obsessive belief; how reasonable the belief is; how weak and strong the belief has fluctuated over the past week; how accurate the belief is; the extent to which others share the same beliefs; how the patient attributes similar or differing beliefs in other people; how effective and important the compulsions are; the extent to which their disorder has caused their obsessive belief; and their degree of resistance toward the belief on a 1 to 10 scale. The average of the 11 items provides an estimate of one's degree of OVI, where higher scores represent greater levels of OVI. | change from baseline at 16 weeks | 
| assess change in level of overvalued ideation | The Over-Valued Ideas Scale (OVIS) is an 11-item clinician administered scale assess severity of overvalued ideation. These include how strong obsessive belief; how reasonable the belief is; how weak and strong the belief has fluctuated over the past week; how accurate the belief is; the extent to which others share the same beliefs; how the patient attributes similar or differing beliefs in other people; how effective and important the compulsions are; the extent to which their disorder has caused their obsessive belief; and their degree of resistance toward the belief on a 1 to 10 scale. The average of the 11 items provides an estimate of one's degree of OVI, where higher scores represent greater levels of OVI. | change from baseline at 6 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
overvalued ideation, treatment acceptability, treatment adherence, treatment outcome, treatment resistance, treatment satisfaction, insight, cognitive therapy, inference based cognitive therapy, exposure and response prevention