Comorbid somatic symptoms and functional status in patients with fibromyalgia and chronic fatigue syndrome: Sensory amplification as a common mechanism

Background: Somatic symptoms are common in conditions such as fibromyalgia (FM) and chronic fatigue syndrome (CFS). Objective: Authors investigated a potential shared pathologic mechanism: a generalized perceptual abnormality where there is heightened responsiveness to varied sensory stimulation, including pain. Method: A composite measure of sensory sensitivity was created and compared with measures of somatic symptoms, comorbid psychological disturbances, and self-reported physical functioning in 38 patients with FM and/or CFS. Results: Sensory amplification influenced physical functioning indirectly through pain intensity, and physical symptoms and fatigue also independently contributed to physical functioning. Conclusion: Sensory amplification may be an underlying pathophysiologic mechanism in these disorders that is relatively independent of depression and depressive symptoms.