Fear driven compulsive behaviour is associated with worse long-term outcome in obsessive–compulsive disorder

Objectives: In this retrospective study of patients with obsessive–compulsive disorder (OCD), we assessed the relationship between different motivational drivers of compulsive behaviours and the response to naturalistic treatments (based mostly on high dose serotonin reuptake inhibitors [SRIs]). Methods: Seventy-six OCD patients were assessed with a structured diagnostic interview; the Habit, Reward and Fear Scale-Revised (HRFS-R); the Yale-Brown Obsessive–Compulsive Scale (YBOCS); the Beck Depression Inventory (BDI); and the OCD Retrospective Assessment of Treatment Response (RATS), which includes information on SRIs administration (e.g., dose and duration of their use), augmentation strategies (such as antipsychotic use or exposure and response prevention intervention), and pre-treatment YBOCS scores. Patients were naturalistically followed up for a mean of 7.28 (SD 5.51) years. Results: Analysis revealed that the fear subscore of the HRFS was the only significant predictor (among a detailed battery of demographic, clinical and treatment factors) independently associated with greater delta (pre-treatment minus post-treatment) YBOCS scores. Conclusions: In contrast to predictions (based on existing models), poorer treatment response was not associated with increased habit scores in the HRFS. Future longitudinal studies are needed to confirm whether increased fear as a driver for ritualistic behaviours is able to predict worse outcomes in OCD samples.