Background and aims Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is challenging to live with, often accompanied by pervasive fatigue and pain, accompanied by decreased quality of life (QoL) as well as anxiety and/or depression. Associations between higher pain, lower QoL and higher anxiety and depression have been shown in patients with various chronic pain disorders. Few studies have however examined such associations in a sample of patients with ME/CFS. The aims of the current study were to examine the impact of pain levels and compare levels of pain, health related QoL, anxiety and depression between patients with ME/CFS and healthy controls. In addition, the study aimed and to examine these relationships within the patient group only. Methods This is a cross-sectional questionnaire based study comparing 87 well-diagnosed patients with ME/CFS with 94 healthy controls. The De Paul Symptom Questionnaire (DSQ), the Medical Outcomes Study Short-Form Surveys (SF-36) and the Hospital Anxiety and Depression Scale (HADS) were used to examine and compare pain, physical function, QoL, anxiety and depression in patients and healthy controls. Further the pain variables were divided into pain total, pain intensity and a pain frequency score for analyses of the above mentioned variables within the patient group only. Results Significantly higher levels of pain, anxiety and depression, and lower levels of QoL were found in the patient group compared with healthy controls. For the patient group alone, pain was significantly associated with lower QoL in terms of physical functioning, bodily pain, general health functioning, vitality and social functioning capacity. In this patient sample, only frequency of joint pain showed significant difference in psychological variables such as depression and anxiety - depression combined. Conclusions ME/CFS patients differ significantly from healthy controls in pain, health related QoL, anxiety and depression. Pain is significantly associated with reduced QoL and overall a lower level of functioning. The relation between pain and anxiety and depression appears less clear. Implications Pain is for many ME/CFS patients associated with reduced physical functioning and reduced QoL. A thorough pain assessment can therefore be essential for clinicians, and subsequent medical pain treatment combined with good pain coping skills may increase functioning level and QoL for these patients. The link between joint pain and psychological factors should also be focused in clinical practice in terms of mapping and counseling. Pain should be further examined to understand the importance it may have for functioning level as reduced function is a main criteria when diagnosing the patients.
Keywords: CFS; ME; anxiety; depression; pain; pain frequency; pain intensity; physical functioning; quality of life.