Impact of symptom focusing and somatosensory amplification on persistent physical symptoms: A three-year follow-up study

Objective: The somatosensory amplification theory considers symptom focusing and somatosensory amplification as important perpetuating factors of persistent physical symptoms. We investigated whether symptom focusing and somatosensory amplification were associated with symptom severity and mental and physical functioning over a three-year period in patients with persistent physical symptoms (PPS). Methods: Baseline, 6-, 12-, 24- and 36-months follow-up data from the PROSPECTS study, a prospective cohort consisting of 325 patients with PPS, were used. We applied longitudinal mixed model analyses to investigate if symptom focusing (CBRQ Symptom Focusing Subscale) and somatosensory amplification (Somatosensory Amplification Scale) at baseline were associated with symptom severity (PHQ-15), mental and physical functioning (RAND-36 MCS and PCS) over three years, using all measurements. Results: Symptom focusing was associated with increased symptom severity and lower mental and physical functioning over time. Somatosensory amplification at baseline was associated with increased symptom severity and lower mental and physical functioning over time. Effect sizes were small. Associations with baseline symptom focusing decreased over time, associations with baseline somatosensory amplification were more stable. There was no interaction effect of both constructs, but they partly overlapped. Conclusion: This is the first study to show that over an extended period, symptom focusing and somatosensory amplification are associated with symptom severity and lower mental and physical functioning in patients with PPS. These results support the impact of both symptom focusing and somatosensory amplification on the perpetuation of symptoms and lowered mental and physical functioning in individuals with PPS.