Four-day Intensive Treatment Versus Standard Cognitive Behavioral Therapy for Adults With Obsessive-compulsive Disorder

The goal of this clinical trial is to compare a novel, condensed version of cognitive behavioral therapy (Bergen 4-Day Treatment, B4DT) to the gold standard psychological treatment (gold-standard CBT) for obsessive compulsive disorder (OCD).

The main question it aims to answer is:

• Is B4DT non-inferior to standard cognitive behavioral therapy (CBT) with regard to OCD symptoms 14 weeks after treatment start?

Adult patients with obsessive compulsive disorder will be randomly assigned to receive either gold standard CBT one to two times per week for 14 weeks, or 4 days of B4DT during one week.

Obsessive-compulsive disorder is a persistent and disabling psychiatric disorder. Individual cognitive behavioral therapy (CBT) with exposure and response prevention (ERP) is an effective treatment for OCD and is recommended as a first-line intervention. However, patients need to remain in treatment for several months and even after that, around 50% remain symptomatic despite this lengthy treatment. In response to this, a novel, condensed version of CBT, B4DT, has been developed. B4DT has shown promising results in several uncontrolled trials and one randomized controlled trial with inactive control, however it has yet to be directly compared to gold-standard individual CBT.

This single blind, randomized controlled trial with 120 patients (60 per arm) will compare B4DT to gold standard CBT. The primary outcome is the blind-rater administered Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). The investigators hypothesize that B4DT will be non-inferior to gold standard CBT 14 weeks after treatment start. The non-inferiority margin is set at 4 points on the Y-BOCS.

Secondary outcomes are cost effectiveness, speed of response, response and remission rates, dropout rate, and negative effects. The investigators hypothesise that participants that receive B4DT will improve faster than patients that receive standard CTB, but for the rest of the secondary outcomes, the investigators have no directed hypotheses.

A more detailed preregistration, and all analysis scripts, are available at Open Science Framework (https://osf.io/w5bfp/).

Eligibility Criteria:
Inclusion Criteria:

1. ≥ 18 years of age.
2. Primary diagnosis of OCD according to the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5).
3. Clinician-rated Y-BOCS score of ≥ 16
4. Written informed consent.
5. To be willing and able to attend treatment at any one of the two treatment clinics, regardless of the clinic where the initial assessment took place (the two clinics are located at different locations in Stockholm, about 20 Km apart).
6. Be fluent in Swedish.

Exclusion Criteria:

1. Other psychological treatment for OCD planned during trial period.
2. Completed CBT with ERP for OCD in the last 12 months.
3. Changes in psychotropic medication within the last 2 months.
4. Bipolar disorder.
5. Psychosis.
6. Alcohol or substance dependence.
7. Organic brain disorder.
8. Hoarding disorder or OCD with primary hoarding symptoms.
9. Suicidal ideation that would warrant close monitoring.