Functional Somatic Disorders, Their Subtypes, and Their Association With Self-Rated Health in the German General Population

Objective The heterogeneous conceptualizations and classifications of persistent and troublesome physical symptoms impede their adequate clinical management. Functional somatic disorder (FSD) is a recently suggested interface concept that is etiologically neutral and allows for dysfunctional psychobehavioral characteristics as well as somatic comorbidity. However, its prevalence and impact are not yet known. Methods We analyzed 2379 participants (mean age = 48.3 years, 52.5% female) from a representative German community survey using operationalized FSD criteria. These criteria defined FSD types based on somatic symptom count, type, and severity assessed by the Bodily Distress Syndrome Checklist. In addition, the associations of those types with health concerns, comorbidity, psychological distress, and self-rated health were determined. Results There were four clearly demarcated groups with no relevant bothering symptoms, with one or with few bothering symptoms from one organ system, and with multiple bothering symptoms from at least two organ systems. Psychological distress, health concerns, and comorbidity steadily increased, and self-rated health decreased according to the number and severity of symptoms. Somatic symptom burden, health concerns, and comorbidity independently predicted self-rated health, with no interaction effect between the latter two. Conclusions Our data support an FSD concept with two severity grades according to persistent and troublesome symptoms in one versus more organ systems. The delimitation of subtypes with psychobehavioral characteristics and/or with somatic comorbidity seems useful, while still allowing the demarcation of a group of participants with high symptom burden but without those additional characteristics.