The Impact of Expectations and Framing on the course of Symptom Severity in Somatic Symptom Disorder-Ecological Momentary Assessment from the SOMA.SSD Study.

PURPOSE: Symptom expectations are considered contributing mechanisms for underlying persistent somatic symptoms in somatic symptom disorder. Expectation framing has been suggested as a promising technique to modify expectations. However, the short-term interplay between symptom expectations, expectation framing, and symptom severity in patients with somatic symptom disorder remains unexplored. METHODS: In this study, 217 patients with somatic symptom disorder participated in a 10-day smartphone-based ecological momentary assessment. Participants were randomized to one of two expectation framing groups either receiving prompts for the expected impairment due to somatic symptoms or for expected freedom from impairment. Symptom expectations and symptom severity were assessed three times daily. RESULTS: Latent growth curve model analyses showed slight decreases in symptom expectations (slope = -0.08, z = -2.24, p < 0.050) and symptom severity (slope = -0.08, z = -2.20, p < 0.050) over time. Growth trajectories for symptom expectations and symptom severity were strongly associated. Symptom severity decreased more rapidly among participants with lower initial symptom expectations compared to those with higher expectations (β = -0.13, z = -2.69, p < 0.010). No significant effects were found for expectation framing. CONCLUSIONS: These findings highlight the associations between symptom expectations and somatic symptoms. Modifying expectations may be a promising factor for somatic symptom persistence, warranting further investigation into longer timeframes, more efficient strategies for expectation modification, and clinical application.