Preliminary effectiveness of the Bergen 4-day treatment for OCD in Iceland.

The Bergen 4-day treatment (B4DT) for obsessive-compulsive disorder (OCD) is a concentrated form of exposure and response prevention that has been evaluated and implemented nationwide in Norway. Its effectiveness has yet to be fully established in other countries. A total of 86 patients with OCD underwent the treatment at the Icelandic Anxiety Centre (KMS) from 2018 to 2023. Of these, 61.6% were classified as having severe symptoms, and 38.4% with moderate symptoms. Of the sample, 72.1% had previously received psychological treatment for OCD and 86.0% had at least one comorbid disorder, depression being the most common (50.0%). Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was administered pre-treatment, posttreatment, and at 3-month follow-up, along with measures on general anxiety, depression, and occupational impairment. The mean score on Y-BOCS was 30.5 (SD = 3.6) pre-treatment, 10.6 (SD = 4.1) posttreatment and 10.9 (SD = 5.4) at 3-month follow-up. By the end of treatment, 94.9% of the patients had responded and 68.0% were in remission. At the 3-month follow-up, 92.5% were responders and 67.9% remitters. Participants were satisfied with the treatment and had improved in terms of occupational functioning, which was maintained at follow-up. These preliminary results suggest that the B4DT may be a swift and effective treatment format for OCD.