Symptom expectations as a clinical target in somatic symptom disorder: Cross-sectional evidence from the SOMA.SSD study

BACKGROUND: Symptom expectations influence symptom severity in patients with pain disorders through nocebo and placebo mechanisms. Similar associations have been suggested for patients with somatic symptom disorder (SSD). While evidence underlines the significance of expectations for symptom experience, yet little is known about the nature of these expectations in SSD or about the psychological and biological factors that shape them. METHODS: Patients diagnosed with SSD participated in a structured on-site assessment at the psychosomatic outpatient clinic of the University Medical Center Hamburg-Eppendorf. The assessment included standardized questionnaires, a physical examination, and a clinical interview. Descriptive statistics and multiple regression analyses were conducted on symptom impairment expectation and symptom-specific expectation measures. RESULTS: A total of N = 241 patients participated in this study. The majority of patients (66.8% female, mean age = 44.5 years) reported negative short-term symptom expectations (54%). Patients with more negative expectations also reported greater somatic symptom severity, higher depression and anxiety severity, increased symptom-related distress, and higher symptom-related disability. Symptom-related disability was found to have the largest association with symptom impairment expectations (short-term: β = 0.46, p < 0.001, long-term: β = 0.26, p < 0.001), whereas symptom severity was associated with symptom-specific expectations the most (β = 0.66, p < 0.001). CONCLUSION: Negative symptom expectations are associated with elevated psychological burden in patients with SSD, indicating a clinically relevant subgroup that may benefit from expectation-focused interventions.