Chronic fatigue syndrome (CFS)/Myalgic Encephalomyelitis (ME) and Fibromyalgia (FM): the foundation of a relationship

Introduction
Chronic fatigue syndrome (CFS)/Myalgic Encephalomyelitis (ME) and fibromyalgia (FM) are both debilitating syndromes with complex polysymptomatology. Early research infers that a relationship may exist even though the diagnosis provided may influence the management trajectory. In the absence of a diagnostic test and treatment, this study aims to confirm the symptoms and their severity, which may infer a relationship and influence future research.

Method
A quasi-experimental design was utilised, using Internet-based self-assessment questionnaires focusing on nine symptom areas: criteria, pain, sleep, fatigue, anxiety and depression, health-related quality of life, self-esteem and locus of control. The questionnaires used for data collection are as follows: the American Centre for Disease Control and Prevention Symptom Inventory for CFS/ME (American CDC Symptom Inventory); the American College of Rheumatology (ACR) Criteria for FM; Fibromyalgia Impact Questionnaire (FIQ); McGill Pain Questionnaire (MPQ); Multidimensional Fatigue Inventory (MFI); Pittsburgh Sleep Quality Index (PSQI); Health-Related Quality of Life SF-36 V2 (HRQoL SF-36 V2); Hospital Anxiety and Depression Scale (HADS); Multidimensional Health Locus of Control (MHLOC) and the Rosenberg Self-Esteem Scale (RSES).

Setting and participants
Participants were recruited from two distinct community groups, namely CFS/ME (n = 101) and FM (n = 107). Participants were male and female aged 17 (CFS/ME mean age 45.5 years; FM mean age 47.2 years).

Results
All participants in the CFS/ME and FM groups satisfied the requirements of their individual criteria. Results confirmed that both groups experienced the debilitating symptoms measured, with the exception of anxiety and depression, impacting on their quality of life. Results suggest a relationship between CFS/ME and FM, indicating the requirement for future research.