Four clinical profiles of adult outpatients with somatic Symptom Disorders and Related Disorders (SSRD). A latent class analysis.

OBJECTIVE

To obtain more insight into the patterns of co-occurring symptoms, biomarkers and predictors in Somatic Symptom Disorders and Related Disorders (SSRD) and to identify subgroups with profiles that might allow for personalised treatment.

METHODS

Cross-sectional study design with Latent class analysis (LCA) to determine different subgroups in a cohort of 239 outpatients with SSRD in 3 steps: 1) building a latent class model; 2) assigning subjects to the latent classes that suited them best based on their posterior probability; 3) investigating the associations between these classes and personal characteristics such as age, gender, somatic comorbidity and general health perception.

RESULTS

Four classes with clinically relevant profiles were found. One with trauma plus elevated inflammation biomarkers, high somatic symptom levels, pain and comorbid depression and anxiety. One with pain plus elevated biomarkers, depression and anxiety. One with low IL-6 and hsCRP, mostly linked to Illness Anxiety. And one with high pain and high elevated biomarkers, but less probability of other factors, that occurred mostly in men. General health perception was lower in classes with elevated inflammation biomarkers.

CONCLUSIONS

The findings of this first study exploring latent classes in an SSRD sample corroborate the current DSM-5 SSD subclassification for pain and Illness Anxiety Disorder. There is scope to extend the current DSM-5 classification with a subclassification of SSD with trauma, and a subclassification with elevated IL6 or hsCRP, as relevant for developing new personalised treatments addressing trauma or SLI in SSRD. Further research is needed to explore this.