Mindfulness-Based Interventions for OCD (MindOC)

March 3, 2026 updated by: Sunnybrook Health Sciences Centre

Mindfulness-Based Interventions for OCD: Efficacy, Mechanisms, and Biological Predictors of Outcome

Obsessive-compulsive disorder (OCD) is a severe and debilitating anxiety disorder afflicting about 2% of the population. It is characterized by the presence of recurrent obsessions and/or compulsions that are time consuming and cause marked distress and/or impairment. Untreated, OCD runs a chronic and deteriorating course. According to the World Health Organization, OCD is among the top 10 leading causes of disability worldwide. Examination of non-medicinal treatments for OCD has focused on two distinct treatments: exposure and response prevention (ERP) and cognitive therapy (CT), often combined into an integrated cognitive-behavioural treatment (CBT). CBT is considered the first line psychological treatment for OCD, with estimates of response rates of between 70-80%. However, there are a significant number of treatment non-responders and the majority of responders are still left with impairing residual symptoms. One area of investigation that has shown potential benefit for general mood and anxiety disorders has been mindfulness-based interventions (MBIs), yet the potential benefits of MBIs in OCD has been largely unexamined, except for several small preliminary studies that show clinical promise. The purpose of this study is to examine the clinical benefits of a standardized MBI treatment for OCD in a large-scale, multi-site randomized controlled trial. The results of this study will directly determine whether Mindfulness can be considered an effective treatment for OCD. If this study can demonstrate that a short-term mindfulness intervention can significantly reduce the suffering associated with OCD, then the findings could easily be translated into routine clinical care in and out of hospital settings. Results of this study will also potentially add to our understanding of the mechanisms that drive OCD symptoms, improve our knowledge of psychological treatment mechanisms, and elucidate how biological factors influence psychological treatment outcomes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Cognitive Behavioural Therapy (CBT) is a first line psychological treatment for OCD with estimated response rates of between 70-80%. However, there are still a substantial number of treatment non-responders and the vast majority of responders are left with impairing residual symptoms. One new area of investigation that has shown potential benefit for the treatment of OCD has been mindfulness-based interventions (MBIs). This emerging literature provides proof of principle for the delivery and potential efficacy of MBIs for OCD, particularly as an adjunct to CBT, with all studies reporting large (d > .80) treatment effects. To date, only our teams' small, non-controlled pilot study (N=19) has shown promise for a MBI as a stand-alone treatment for OCD separate from CBT (d = 1.10). However, all results to date for MBI treatments for OCD must be interpreted with caution as they have utilized small, underpowered sample sizes, have not included control groups, and failed to control for potentially confounding variables (e.g., medications, self-initiated exposures). The proposed four-year, two-site randomized controlled trial at two of Canada's leading OCD treatment centres (Sunnybrook Health Sciences Centre and St. Joseph's Healthcare Hamilton) that have been involved in developing and piloting MBI treatments for OCD will aim to test whether a structured, Mindfulness-Based Cognitive Therapy (MBCT) intervention for OCD is an efficacious treatment for a large, heterogeneous sample of DSM-5 (Diagnostic Statistical Manual of Mental Disorders 5th edition) diagnosed OCD participants. The primary aim of this proposed study is to examine whether a developed and piloted MBCT treatment for OCD is efficacious when compared to a waitlist condition and to explore its efficacy compared to CBT treatment for OCD. A secondary aim of the study is to examine the putative treatment mechanisms of MBCT. Past research examining treatment mechanisms in CBT for OCD have focused on the reduction of obsessional beliefs, anxiety sensitivity, and safety behaviours in producing better outcomes. In contrast, the hypothesized mechanisms in MBI treatments include the development of mindfulness skills such as acting with awareness, non-reactivity to and non-judging of inner experience, and reduction in mind wandering. The large-scale, powered RCT (randomized control trial) design will permit the examination of whether MBCT and CBT include overlapping or distinct treatment mechanisms. Treatment outcomes will be assessed with standardized measures of OCD symptomatology, general measures of mood and anxiety, a reliable and valid EEG measure to assess cognitive changes across treatment. If this study can demonstrate that a short-term mindfulness intervention can significantly reduce the suffering associated with OCD, then the findings could easily be translated into routine clinical care in and out of Canadian hospital settings. Results of this study will also potentially add to our understanding of the mechanisms that drive OCD symptoms, improve our knowledge of psychological treatment mechanisms, and elucidate how genetic/biological factors influence psychological treatment outcomes.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
420

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8N 4A6
        • St. Joseph's Healthcare Hamilton
      • Toronto, Ontario, Canada, M4N 3M5
        • Sunnybrook Health Sciences Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • experiencing clinically significant obsessive-compulsive symptoms based on the Yale-Brown Obsessive Compulsive Scale (YBOCS; score > 17)
  • if on medications for OCD, must be stabilized, i.e. are currently receiving an adequate dose (equivalent of 40mg/day of fluoxetine) for an adequate duration (at least 8 weeks of treatment) prior to the initiation of the study.

Exclusion Criteria:

  • concurrent diagnosis of a severe mood disorder, schizophrenia or other psychotic disorders, or substance abuse/dependence
  • suspected organic pathology
  • an active comorbid medical condition that may require urgent intervention during the treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cognitive Behaviour Therapy
This study arm will receive 12 weeks of cognitive behaviour therapy as an intervention.
Behavioral: Cognitive Behaviour Therapy (CBT)
Cognitive behavioural therapy (CBT), incorporating exposure/response prevention (ERP) and cognitive therapy, is considered the gold-standard treatment for OCD. The efficacy of CBT has been well established, with numerous studies demonstrating that it leads to significant and lasting reduction in OCD symptoms for the majority of completers.
Experimental: Mindfulness-based Cognitive Therapy
This study arm will receive 12 weeks of a mindfulness-based cognitive therapy intervention, along with open mindfulness sessions via an EEG headset.
Device: Muse
Muse is an EEG headset device created by Interaxxon to track brain waves during mindfulness sessions.
Behavioral: Mindfulness-Based Cognitive Therapy (MBCT)
Mindfulness-based interventions (MBIs) including MBCT, are interventions that incorporate formal and informal mindfulness practice in order to treat mental health concerns.
No Intervention: Waitlist
This study arm will not receive an intervention for 12 weeks.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change from baseline in OCD symptom severity, as measured by the Yale-Brown Obsessive Compulsive Scale (YBOCS)
Time Frame: Baseline to 12 weeks
OCD symptom severity will be measured using the Yale-Brown Obsessive Compulsive Scale (YBOCS).The YBOCS is a standardized rating scale measuring 10 items pertaining to obsessions and compulsions on a 5-point Likert scale ranging from 0 (no symptoms) to 4 (severe symptoms). Both the self-report and clinician interview versions of the YBOCS have been shown to possess high internal consistency and validity.
Baseline to 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in OCD symptomatology, as measured by the OCI-R (Obsessive Compulsive Inventory - Revised).
Time Frame: Baseline to 12 weeks
This self -report short version of the OCI consisting of 18 items measures six distinct factors: Washing, Checking, Ordering, Obsessing, Hoarding and Neutralizing, to chart the change in OCD symptomatology across time.
Baseline to 12 weeks
Change from baseline in the experience of depression, anxiety and stress symptoms, as measured by the DASS-21 (Depression, Anxiety and Stress Scale - 21 items).
Time Frame: Baseline to 12 weeks
Depression, anxiety and stress severity will be measured using the Depression Anxiety Stress Scales-21,a self-report questionnaire comprising three subscales with seven items each for depression, anxiety and stress. The DASS-21 shows high internal consistency, high reliability in distinguishing between depression, anxiety and stress in adults, and good convergent and discriminant validity.
Baseline to 12 weeks
Change from baseline in various attitudes and beliefs related to obsessional thoughts, as measured by the OBQ-44 (Obsessional Beliefs Questionnaire - 44 items).
Time Frame: Baseline to 12 weeks
The Obsessional Beliefs Questionnaire is a 44-item self-report questionnaire designed to assess the extent to which respondents agree or disagree with various attitudes and beliefs related to obsessional thoughts. The OBQ is internally consistent, and evidences good test-retest reliability, convergent validity, and discriminant validity.
Baseline to 12 weeks
Change from baseline in aspects of mindfulness, as measured by the FFMQ (Five Facet Mindfulness Questionnaire).
Time Frame: Baseline to 12 weeks
The Five Facet Mindfulness Questionnaire is a self-report questionnaire containing 39 items that assess five aspects of mindfulness: observing, describing, acting with awareness, non-judgment of inner experiences, and non-reactivity to inner experience.
Baseline to 12 weeks
Change from baseline in functional health and well-being, as measured by the SF-36 Health Survey (Short Form 36 item Health Survey).
Time Frame: Baseline to 12 weeks
The SF-36 Health Survey is a brief questionnaire containing 36 items about functional health and well-being. The reliability and validity of the SF-36 have been well documented. It has demonstrated good treatment sensitivity
Baseline to 12 weeks
Change from baseline in the degree which individuals find distress intolerable, as measured by the DTS (Distress Tolerance Scale).
Time Frame: Baseline to 12 weeks
The Distress Tolerance Scale is a 15-item self-report questionnaire that measures the degree to which individuals find distress intolerable, unacceptable, impairing, and necessary to avoid. Distress tolerance has been linked to OCD.
Baseline to 12 weeks
Change from baseline in the fear of consequences of anxiety, as measured by the ASI-3 (Anxiety Sensitivity Index).
Time Frame: Baseline to 12 weeks
The Anxiety Sensitivity Index-3 is an 18-item self-report measure of the degree to which individuals fear the consequences of anxiety. It is composed of three subscales: fear of the physical, social, and cognitive consequences of anxiety.
Baseline to 12 weeks
Change from baseline in the time spent ruminating, as measured by the RRS (Ruminative Response Scale).
Time Frame: Baseline to 12 weeks
The Ruminative Response Scale is a frequently used 22-item measure of the amount to which participants are engaging in rumination, or repetitive, passive, and negative self-focus.
Baseline to 12 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change from baseline in OCD symptomatology, as measured by the EEG headset device "Muse".
Time Frame: Baseline to 12 weeks
Participants will be instructed to use the "Muse" EEG headset for open, unguided mindfulness sessions. The device will measure alpha and beta band oscillatory power and how it will change over the 12 weeks of treatment intervention.
Baseline to 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Sunnybrook Health Sciences Centre

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
St. Joseph's Healthcare Hamilton
McMaster University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Neil A Rector, PhD, Sunnybrook Health Sciences Centre

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 9, 2021

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 31, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 31, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 7, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RN440237-452052

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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