The Bergen 4-day treatment for OCD in Iceland: 12-month follow-up

The Bergen 4-day treatment (B4DT) for obsessive compulsive disorder (OCD) is a concentrated form of exposure and response prevention that has been implemented at the Icelandic Anxiety Centre. The aim of the present study was to assess 12-month results of 86 participants undertaking the treatment. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was administered at pre-, post-, and 3- and 12-month follow-up, accompanied by measures on generalised anxiety (GAD-7), depression (PHQ-9), and functional impairment (WSAS). The mean pre-treatment score on Y-BOCS was 30.5 ( SE =0.5), the post-treatment score was 10.7 ( SE =0.4), and the 12-month follow-up score was 11.5 ( SE =0.9). There was no significant difference in Y-BOCS scores from post-treatment to 3- and 12-month follow-up, which indicates that treatment gains were maintained over time. Functional impairment, along with symptoms of anxiety and depression, decreased significantly from pre- to post-treatment, with further reductions in functional impairment observed at the 12-month follow-up. All participants completed treatment, and at 12-month follow-up, 83.7% had responded and 67.4% recovered. Among the participants that had responded or remitted at post-treatment, 22% had a worse outcome at 12-month follow-up, but 54% of the participants in the response or no change categories at post-treatment had a better outcome at follow-up. These results support the effectiveness and long-term benefits of the B4DT when implemented outside of its country of origin. Key learning aims (1) The Bergen 4-day treatment (B4DT) is a highly intensive format of exposure and response prevention (ERP) for OCD. (2) Treatment gains from the B4DT for OCD are sustained for at least 12 months, with 67% of patients remaining recovered and 84% showing improvement. (3) Approximately half of those who do not fully benefit initially experience further improvement by the 12-month follow-up. (4) Drop-out rates are negligible, which is unusual for exposure and response prevention. (5) The B4DT demonstrates effectiveness beyond its country of origin.