ZeroOCD: Learn to Overcome Contamination OCD With Your Smartphone (ZeroOCD)

ZeroOCD: Learn to Overcome Contamination OCD With Your Smartphone: An Augmented Reality Cognitive Behavioral Therapy App for Obsessive-Compulsive Disorder: Randomized Controlled Trial

This study is a three-arm randomized controlled trial designed to evaluate the efficacy of a smartphone-based augmented reality (AR) cognitive behavioral therapy (CBT) app, called ZeroOCD, for individuals with elevated contamination-related obsessive-compulsive disorder (OCD) symptoms. The AR-CBT app will be compared to both an active control condition (manualized CBT via videoconferencing) and a waitlist control group.

Study Overview

• Status: Not yet recruiting
• Conditions: Obsessive Compulsive Disorder (OCD)
• Intervention / Treatment: Behavioral: ZeroOCD; Behavioral: Videoconferencing CBT

Detailed Description

Obsessive-compulsive disorder (OCD) is a prevalent and disabling condition, with contamination fears being one of its most common presentations. While Cognitive-Behavioral Therapy (CBT) with Exposure and Response Prevention (ERP) is a first-line treatment, many individuals face barriers to accessing it, such as cost, stigma, and availability of therapists. This multicenter trial, conducted in the Netherlands, Belgium, Sweden, and Switzerland, will recruit a total of 189 individuals experiencing contamination-related obsessive-compulsive symptoms. Participants will be randomized to one of three study conditions (allocation ratio 2:2:1): The first group (n = 75) receives access to ZeroOCD, an augmented reality (AR) based smartphone application, which provides CBT and ERP for contamination fears, along with three therapist support sessions via videoconferencing. The second group (n = 75) receives weekly CBT for OCD via videoconferencing (nine sessions in total). The third group is a waitlist control group (n = 39), who will receive access to the smartphone application with minimal therapist support on request after 10 weeks in the study. The study aims to evaluate the effectiveness of the ZeroOCD intervention compared to both a waitlist control and videoconferencing CBT, and to assess cost-effectiveness and usability. Assessments are conducted at baseline, 10 weeks post-randomization, and at 6-month follow-up for the intervention groups. Participants in the waitlist group complete assessments at baseline, 10 weeks post-randomization, and receive access to the ZeroOCD intervention 10 weeks after randomization. Further, the waitlist group will complete an assessment 20 weeks post-randomization. The study is a multicenter trial involving participants in Switzerland, the Netherlands, Belgium, and Sweden.

• Study Type: Interventional
• Enrollment (Estimated): 189
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Tar Donker, PhD; Phone Number: 0205988265; Email: t.donker@vu.nl

Study Locations

• Belgium
  • Mechelen, Belgium
    • Thomas More Mechelen
    • Contact: Tom van Daele, PhD; Phone Number: 32 2 218 16 20; Email: tom.vandaele@thomasmore.be
• Netherlands
  • North Holland
    • Amsterdam, North Holland, Netherlands, 1081 BT
      • Vrije Universiteit Amsterdam
• Sweden
  • Stockholm, Sweden
    • Stockholm University
    • Contact: Per Carlbring, PhD; Phone Number: 08-16 39 20 of 070-666 7 666; Email: per.carlbring@psychology.su.se
• Switzerland
  • Bern, Switzerland
    • UBERN
    • Contact: Thomas Berger, PhD; Phone Number: +41 31684 34 07; Email: thomas.berger@unibe.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• • OCD symptoms, mean score > 7 on the Yale Brown Obsessive Compulsive Scale (Y-BOCS)

  • Fear of contamination OCD symptoms, mean score > 6 on the Padua Inventory contamination fear subscale (PI)
  • Having access to a compatible smartphone
  • Having an internet connection
  • Proficiency in one of the countries' languages (i.e., Dutch/ Flemish, German, or Swedish)
  • Willing to participate in the research study and provide informed consent

Exclusion Criteria:

• • Having been diagnosed with bipolar or psychotic disorder (self-report)

  • Severe depressive symptoms (Patient Health Questionnaire, PHQ-9, score > 20)
  • Reporting suicidality (PHQ-9, item 9 > 2 points at screening)
  • Fear of contamination due to disorder other than OCD (clinical judgment based on results from the Yale Brown Obsessive Compulsive Scale, Y-BOCS, Generalized Anxiety Disorder-7 items, GAD-7, Short Health Anxiety Inventory, SHAI)
  • Parallel psychological treatment
  • Non-stable dosage of psychoactive medication during the last three months or planned changes during the study period.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ZeroOCD AR-CBT App + 3 therapist support sessions; Participants will use the ZeroOCD smartphone application, which delivers 9 modules of augmented reality exposure therapy and cognitive behavioral therapy principles. This group will also receive 3 videoconferencing sessions with a therapist at the beginning, middle, and end of the 10-week treatment period.	Behavioral: ZeroOCD; The ZeroOCD app contains the following components: psychoeducation, detecting obsessive thoughts, coping with obsessions, goal setting, fear curve explanation, exposure with AR, re-exposure with AR, exposure hierarchy, exposure in real-life, re-exposure in real life and relapse prevention; Other Names: ZeroOCD AR-CBT App + 3 therapist support sessions
Active Comparator: Videoconferencing CBT; Participants will receive 9 weekly sessions of manualized Cognitive Behavioral Therapy with Exposure and Response Prevention (ERP) delivered via videoconferencing by trained therapists.	Behavioral: Videoconferencing CBT; Videoconferencing CBT contains the following chapters: psychoeducation, detecting obsessive thoughts, coping with obsessions, goal setting, fear curve explanation, exposure hierarchy, exposure in real-life, re-exposure in real life and relapse prevention
No Intervention: Waitlist control group; Participants in this group will receive access to the ZeroOCD app with therapist support on request after a 10-week waiting period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
OCD Symptoms (Interview)	Yale-Brown Obsessive Compulsive Scale (Y-BOCS): Change from baseline in the observer-rated severity of OCD symptoms. This is a 10-item, clinician-rated scale that provides separate subtotals for the severity of obsessions and compulsions. Total scores range from 0 to 40, with higher scores indicating more severe symptoms. The Y-BOCS is also used for the eligibility (mean score > 7).	At baseline, At 10 weeks, At 20 weeks (only WL condition) At 24 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
OCD symptoms (Self-report)	4-item Obsessive-Compulsive Inventory (OCI-4): Change from baseline in the self-reported OCD symptom severity. This shorter form of the OCI-R consists of 4 Items that quantify the symptom severity related to OCD. Each item is rated on a scale from 0 to 4, with total scores ranging from 0 to 16, with higher scores indicating more severe symptoms.	At baseline, During treatment (every week) At 10 weeks, At 24 weeks
Fear of Contamination	Padua Inventory (PI) Contamination Fear Subscale: Change from baseline in the self-reported fear of contamination. This is a 10-item subscale that quantifies the severity of contamination-related obsessions, with each item rated on a 5-point Likert scale. A score of 6 or higher on this scale is an inclusion criterion for the study. The PI is also used for the eligibility (mean score > 6).	At baseline, At 10 weeks, At 20 weeks (only WL condition) At 24 weeks
Depression	Patient Health Questionnaire-9 (PHQ-9): Change from baseline in self-reported depressive symptom severity. This is a 9-item measure where each item corresponds to a DSM-5 criterion for major depression. Scores range from 0 to 27, and a score of >20 is an exclusion criterion. The PHQ-9 is also used for the eligibility (severe depressive symptoms: score > 20; suicidality: item 9 score > 2).	At baseline, At 10 weeks, At 24 weeks
Anxiety	Generalized Anxiety Disorder 7-item scale (GAD-7): Change from baseline in self-reported anxiety symptom severity. This is a 7-item measure with scores ranging from 0 to 21. It will also be used at baseline to help determine if contamination fears are due to GAD rather than OCD.	At baseline, At 10 weeks, At 24 weeks
Current Distress/Disgust	Subjective Units of Distress Scale (SUDS): Measurement of current distress and disgust levels before, during, and after exposure tasks within the ZeroOCD app. This is an ecological momentary assessment (EMA) where participants rate their distress on a visual analog scale from 0 to 10.	up to ten weeks
Social Functioning	World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0): Change from baseline in self-reported general functioning and disability. This is a 36-item measure that evaluates functioning across six major life domains (e.g., cognition, mobility, life activities).	At baseline, At 10 weeks, At 24 weeks
Health Related Quality of Life	EQ-5D-5L measures change from baseline in self-reported health-related quality of life. This is a 5-item standardized questionnaire that evaluates health status across five domains (e.g., mobility, self-care, pain/discomfort).	At baseline, At 10 weeks, At 24 weeks
Societal Costs of a Treatment	Treatment Inventory of Costs in Patients with Psychiatric Disorders (TiC-P): Change from baseline in the utilization of healthcare services and productivity losses. This is a 36-item self-report measure used for the cost-effectiveness analysis.	At baseline, At 10 weeks, At 24 weeks
Usability	System Usability Scale (SUS): A global assessment of the subjective usability of the ZeroOCD app, measured post-treatment. This is a 10-item questionnaire with total scores ranging from 0 to 100, where higher scores indicate greater perceived usability.	At 10 weeks (only ZeroOCD condition), At 20 weeks (only WL condition)
Treatment Satisfaction	Client Satisfaction Questionnaire (CSQ): A measure of client satisfaction with the received treatment, assessed post-treatment. This is an 8-item self-report measure with total scores ranging from 8 to 32, where higher scores indicate greater satisfaction.	At 10 weeks (only intervention groups)
Realism of AR-Environment	Realism subscale of the IGroup Presence Questionnaire (IPQ): A measure to assess the perceived realism of the augmented reality (AR) environment, administered post-treatment to the ZeroOCD group. This is a 4-item subscale relevant for AR with each item assessed on a 7-point Likert scale (from -3 to 3).	At 10 weeks (only ZeroOCD condition)
Negative Effects of Treatment	Negative Effects Questionnaire (NEQ): A measure to evaluate any negative effects of the psychological treatments, assessed at post-treatment and follow-up. This is a 20-item questionnaire where participants report on the occurrence, negative impact, and attributed cause of potential negative events.	At 10 weeks (only ZeroOCD and CBT condition), at 20 weeks (only waitlist condition)
Usage Data	To understand the dose-response relationship in treatment effectiveness by analyzing how participants interact with the ZeroOCD app. This involves collecting data automatically from the app for participants in the intervention condition. Data points include the frequency and duration of practice during AR exposure, time spent in each module, number of modules and pages completed, and number of log-ins.	up to ten weeks (only ZeroOCD and waitlist condition)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Reasons for discontinuation	Reasons for discontinuation: to understand why participants stop with the treatment before the end of the treatment	up to ten weeks
Socio-demographic information	Socio-demographic questionnaire: To gather participant characteristics and demographics at the start of the study. This questionnaire collects information about participants' age, gender, education level, marital status, employment status, and treatment preference. It also gathers information on current or past psychological treatment and medication to confirm eligibility.	At baseline
Health Anxiety	Short Health Anxiety Inventory (SHAI): A self-report measure to assess the presence of health anxiety at baseline, which is an exclusion criterion if judged to be the primary driver of contamination fears. This is an 18-item measure rated on a scale from 0 to 3.	At baseline

Collaborators and Investigators

• Sponsor: VU University of Amsterdam
• Collaborators: University of Bern; Stockholm University; Thomas More University of Applied Sciences

Study record dates

Study Major Dates

• Study Start (Estimated): September 21, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: September 3, 2025
• First Submitted That Met QC Criteria: September 18, 2025
• First Posted (Estimated): September 26, 2025

Study Record Updates

• Last Update Posted (Estimated): September 26, 2025
• Last Update Submitted That Met QC Criteria: September 18, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Randomized Controlled Trial; Smartphone; Cost-effectiveness; Obsessive Compulsive Disorder; Augmented Reality
• Additional Relevant MeSH Terms: Mental Disorders; Anxiety Disorders; Obsessive-Compulsive Disorder
• Other Study ID Numbers: ZeroOCD/FP-1478

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Deidentified participant data
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No