High prevalence of somatisation in ICD-11 complex PTSD: A cross sectional cohort study

Background: While research demonstrates that somatisation is highly correlated with post-traumatic stress disorder (PTSD), the relationship between International Classification of Diseases 11th edition (ICD-11) PTSD, complex PTSD (CPTSD) and somatisation has not previously been determined. Objective: To determine the relationship between frequency and severity of somatisation and ICD-11 PTSD/ CPTSD. Method: This cross-sectional study included 222 individuals recruited to the National Centre for Mental Health (NCMH) PTSD cohort. We assessed rates of Patient Health Questionnaire 15 (PHQ-15) somatisation stratified by ICD-11 PTSD/CPTSD status. Path analysis was used to explore the relationship between PTSD/CPTSD and somatisation, including number of traumatic events, age, and gender as controls. Results: 70% (58/83) of individuals with CPTSD had high PHQ-15 somatisation symptom severity compared with 48% (12/25) of those with PTSD (chi-square: 95.1, p value <0.001). Path analysis demonstrated that core PTSD symptoms and not disturbances in self organisation (DSO) symptoms were associated with somatisation (unstandardised coefficients: 0.616 (p-value 0.017) and - 0.012 (p-value 0.962) respectively. Conclusions: Individuals with CPTSD have higher somatisation than those with PTSD. The core features of PTSD, not the DSO, characteristic of CPTSD, were associated with somatisation.

Automated summary

This study found that individuals with CPTSD had higher somatisation severity compared to those with PTSD, and somatisation was associated with core PTSD symptoms rather than CPTSD characteristic disturbances in self-organization.