ZeroOCD: Learn to Overcome Contamination OCD With Your Smartphone

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.

• OCD symptoms (Self-report) [Time frame: At baseline, During treatment (every week) At 10 weeks, At 24 weeks]
• Fear of Contamination [Time frame: At baseline, At 10 weeks, At 20 weeks (only WL condition) At 24 weeks]
• Depression [Time frame: At baseline, At 10 weeks, At 24 weeks]
• Anxiety [Time frame: At baseline, At 10 weeks, At 24 weeks]
• Current Distress/Disgust [Time frame: up to ten weeks]
• Social Functioning [Time frame: At baseline, At 10 weeks, At 24 weeks]
• Health Related Quality of Life [Time frame: At baseline, At 10 weeks, At 24 weeks]
• Societal Costs of a Treatment [Time frame: At baseline, At 10 weeks, At 24 weeks]
• Usability [Time frame: At 10 weeks (only ZeroOCD condition), At 20 weeks (only WL condition)]
• Treatment Satisfaction [Time frame: At 10 weeks (only intervention groups)]
• Realism of AR-Environment [Time frame: At 10 weeks (only ZeroOCD condition)]
• Negative Effects of Treatment [Time frame: At 10 weeks (only ZeroOCD and CBT condition), at 20 weeks (only waitlist condition)]