Is panic disorder associated with clinical severity of fibromyalgia? A preliminary study in a tertiary-care centre

OBJECTIVES: To investigate the influence of panic disorder (PD) with/without agoraphobia on the clinical severity of fibromyalgia (FM). METHODS: Eighty-one patients with FM, among those consecutively referring to a tertiary-care setting, were included in this cross-sectional study. Psychiatric diagnoses were made by the structured clinical interview in accordance with the 4th-TR version of the diagnostic and statistical manual of mental disorders. The clinical severity of FM was measured by means of the following self-administered scales: Fibromyalgia Impact Questionnaire (FIQ), Fibromyalgia Assessment Status (FAS), Health Assessment Questionnaire (HAQ). RESULTS: A final sample of 66 females with FM with or without past PD was included in the analyses. The two groups did not significantly differ in age, years of education, length of illness or medication distribution. We did not find significant differences between the two groups in the FIQ and FAS scale scores, whereas subjects with FM and past PD showed significantly higher HAQ scale scores than those without past PD (p<.001). CONCLUSIONS: A history of PD in patients with FM increases the severity of functional impairment in performing a wide range of daily-life activities, as measured by the HAQ scale, with no effects on the severity of other clinical dimensions of FM. Potential underlying mechanisms and clinical implications will be discussed.