The relationship among psychological and psychophysiological characteristics of fibromyalgia patients.

UNLABELLED: This study examined the relationship of psychophysiological response patterns in fibromyalgia with psychological characteristics and comorbid mental disorders. Surface electromyographic data, systolic and diastolic blood pressure, heart rate (HR), and skin conductance levels were recorded continuously during baseline, stress, and relaxation tasks. Cluster analysis revealed 4 subgroups of patients who differed on pain characteristics and cognitive, affective, and behavioral responses to pain and stress. The largest group (46.7%) was characterized by elevated blood pressure levels and stress reactivity (a disposition assumed to be a vulnerability factor for the development of diseases) associated with pain, anxiety, physical interference, low activity, and pain behaviors. A second group (41.6%) showed low baseline blood pressure and reactivity, and high activity and stress. A third group (9.2%) displayed high baseline skin conductance level, reactivity, and depression, and a fourth small group (2.5%) displayed elevated baseline electromyographic response and reactivity with high levels of anxiety and depression. These data suggest that unique psychophysiological response patterns are associated with psychological coping and mental disorders in fibromyalgia patients. The identification of the mechanisms that contribute to these group differences will further our understanding of the mechanisms involved in the development and maintenance of fibromyalgia and suggest differential treatment strategies. PERSPECTIVE: This article presents psychological characteristics and comorbidity with mental disorders of psychophysiological subgroups of fibromyalgia patients. This mechanistic analysis will assist scientific identification of systems-based pathways that contribute to autonomic and stress mechanisms that mediate chronic pain. Demonstration of distinct, homogeneous subgroups is an important step towards personalized, mechanism-oriented treatments.