Abstract
BACKGROUND: Persistent physical symptoms are common and often result in disability and high healthcare use. To capture how such symptoms co-occur, Bodily Distress Syndrome (BDS, also called Functional Somatic Disorders) was developed as an empirically derived construct, in contrast to consensus-based syndromes such as fibromyalgia and chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). BDS is distinct from ICD-11 Bodily Distress Disorder and reflects the multisystem symptom pattern described in the Functional Somatic Disorder framework. However, its prevalence, symptom structure and prognostic relevance in pain populations have not been mapped. METHODS: This study included 3762 individuals referred to a tertiary pain clinic. At baseline, participants reported standardised measures of fatigue, insomnia, pain catastrophizing, psychological distress, perceived injustice, health-related quality of life and disability. After 12 months, they reported disability and perceived change. BDS severity was classified from predefined symptom cluster criteria. We examined prevalence, clinical correlates and prognostic utility. RESULTS: 92.5% met the criteria for moderate or severe BDS. They reported more severe physical symptoms, elevated psychological distress and reduced functioning than those not meeting the criteria. Severe BDS was more common among women, those without higher education and individuals outside the workforce. After 12 months, individuals with BDS showed less improvement in functioning and reported lower perceived treatment benefit. CONCLUSION: BDS was common in this outpatient hospital cohort and may offer a clinically useful lens for capturing multisystem complexity in specialised pain services. Incorporating BDS screening into routine assessment could help identify individuals with complex symptoms and support more mechanism-oriented treatment approaches. SIGNIFICANCE STATEMENT: Bodily Distress Syndrome (BDS) is highly prevalent in tertiary pain care and linked to more severe symptoms, psychosocial burden and poorer long-term outcomes. The findings support BDS as a clinically useful framework for identifying patients with complex symptom profiles and for guiding interdisciplinary, mechanism-oriented approaches to pain management.