Fibromyalgia (FM) is a chronic pain syndrome of unknown etiology. It was previously suggested that patients with fibromyalgia were, in early life, often subjected to either psychological or physiological trauma. It is, in general, known that early life experiences and attachment to primary caregivers can influence physiological function in adult life, especially those functions related to stress vulnerability. Many studies have been performed on fibromyalgia patients but most of them investigated either psychological or physiological aspects. The purpose of this study was to investigate the psychological profile (attachment style, preferred way of thinking as well as prevalence of depression and anxiety) and physiological aspects (autonomic nervous system function and cortisol levels) simultaneously in an attempt to see whether a link exists between the two aspects and whether a specific psychoneurological profile could be discerned for fibromyalgia patients. Sixteen patients (14 females, 2 males) with fibromyalgia, and 15 age- and sex-matched controls (13 females, 2 males) were studied. Patients were diagnosed according to the American College of Rheumatology (ACR, 1990) criteria for fibromyalgia. The Patient Health Questionnaire gathered information on the patient’s past health problems, operations, accidents and the prevalence of traumatic events. The Fibromyalgia Impact Questionnaire and Review of Current Symptoms Questionnaire were completed to assess the severity of the disorder. The Experiences in Close Relationships – Revised Questionnaire determined attachment styles. Hemisphere dominance (preferred way of thinking) was evaluated by the Herrmann Brain Dominance Instrument (HBDI), heart rate variability (HRV) by recording R-R intervals and calculating time and frequency domain parameters and salivary cortisol levels by ELISA. Significant differences were seen between patients and controls for cortisol levels; the total number of symptoms; the number of adverse events in lifetime; anxiety and avoidance subscales of the ECR-R; FIQ total scores; and scores for scales within the FIQ. R-R spectral analysis revealed distinct lowered overall HRV in patients. An orthostatic test revealed a weakened shift towards sympathetic dominance upon standing. During a psychological stressor (filling out the ECR-R), the patients’ autonomic nervous system failed to respond with lower HRV as with the controls. As far as the hemispheric dominance of the patients was concerned, the majority appeared to be right-brain orientated with thinking styles preferences strongly influenced by limbic functions. Preference for thinking styles influenced by right limbic structures increased during stress. A link existed between anxiety and depression and the severity of the fibromyalgia symptoms. The results of individual psychological and physiological parameters found in this study are largely in concordance of that of other studies. Significant differences exist between the psychoneurological variables of fibromyalgia patients and healthy controls: The patient group in this study were characterised by a high prevalence adverse events, insecure attachment styles, high emotionality in the absence of rationality, multiple somatic symptoms, and altered stress-axes activity reflected in low HRV, an inability to mount an appropriate sympathetic response to acute stressors and elevated baseline cortisol levels. It can be concluded that fibromyalgia patients in the present study presented with a distinct psychoneurological profile. / Dissertation (MSc (Physiology))--University of Pretoria, 2007. / Physiology / unrestricted