Course and predictors of DSM-5 somatic symptom disorder in patients with vertigo and dizziness symptoms – A longitudinal study

Background Somatic symptom disorder (SSD) is a diagnosis that was newly included in DSM-5. Currently, data on the course of SSD are largely lacking. The present study aimed to evaluate the natural course of SSD in a one-year follow-up study in patients with vertigo and dizziness (VD) symptoms. Methods We investigated n = 239 outpatients presenting in a tertiary care neurological setting over a one-year period. Patients had a medical examination at baseline and completed self-report questionnaires, which were re-assessed after 12 months. DSM-5 SSD was assigned retrospectively. We evaluated the prevalence of SSD at baseline and 12-month follow-up and investigated predictors of the persistence of SSD during the study period. Results The prevalence rate of SSD was 36% at baseline and 62% at 12-months follow-up. The persistence rate of SSD was 82% and the incidence rate was high, leading to a markedly increased prevalence rate at follow-up. Risk factors for persistent SSD were a self-concept of bodily weakness (OR: 1.52, 95% CI: 1.30–1.78) and an increase of depression during the study period (OR: 1.11, 95% CI: 1.02–1.22). Further, the diagnosis of an anxiety disorder (OR: 7.52, 95% CI: 1.17–48.23) or both anxiety and depressive disorder (OR: 23.14, 95% CI: 2.14–249.91) at baseline were significant predictors. Conclusions Our findings point out that SSD is highly prevalent in patients with VD symptoms, the incidence of the disorder widely outweighs its remission. Potential predictors of a persistence of SSD are discussed and can be chosen as a focus in therapy.