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

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.

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 12months. 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.

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.

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.