Fibromyalgia (FM) is a chronic syndrome of unknown etiology, complex and variable evolution, provoking generalized pain that can become incapacitating. It affects the biological, psychological, and social spheres, and is an important health problem due to its prevalence, morbidity, and high rates of use and consumption of health resources. FM is described as the existence of generalized pain of more than three months' duration, absence of other causal pathology, and comorbidity with other syndromes and symptoms, such as chronic fatigue, nonremedial sleep, cognitive deficit, and numerous somatic and emotional symptoms, such as anxiety and depression. In 1992, FM was recognized by the World Health Organization and typified in the International Classification of Diseases (CIE-10) within rheumtological diseases. The prevalence of FM in developed countries is between 1 and 4%, and in Spanish population, it is 2.4%, with 4.2% in females and .2% in males. Although many studies agree about the presence of psychopathology in FM, its frequency and intensity are variable and there is little evidence about the premorbid situation of the affected people, and therefore, about role of psychopathology in its pathogenesis. It is known that many people with FM have psychopathological symptoms (anxiety, depression), but the studies differ about whether psychopathology is the origin of FM or whether all people with FM have psychopathologicaldisorders. The goals of the study were to determine possible differences in diverse psychopathological symptoms in people of both sexes with and without FM and to analyze the onset of the symptoms in the biography of people with FM. The study was performed with 190 Spanish participants, 140 with FM (73.7%) and 50 without FM (26.3%). The participants were aged between 28 and 75 years (M= 52.16; SD= 9.18), 10 were male (5.3%) and 180 female (94.7%). A descriptive, comparative, cross-sectional design was used and the 90-Symptoms Checklist Revised (SCL-90-R - Derogatis, 1983/2002) was administered. The ANOVAs confirmed that: (1) compared with people who did not have FM, people with FM of both sexes obtained significantly higher mean scores in all the psychopathological symptoms (somatization, ob session-compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, para noid ideation, psychoticism) and in all three indices. The most frequent symptoms were so ma tization, obsession-compulsion, depression, and anxiety; (2) compared with the nonclinical sample of the test, people with FM had percentile scores greater than or equal many symptoms (somatization, obsessioncompulsion, interpersonal sensitivity, depression, anxiety) and in all the indices. In the Global Severity Index (GSI), 94.3% of FM patients obtained percentiles of greater than or equal 80. However, compared with the clinical sample of the test (psychiatric patients), FM patients only obtained high percentiles (≥ 90) in somatization, and in the GSI, only 30.7% obtained percentiles greater than or equal 80; and (3) only 23.6% of the people with FM presented prior psychiatric/psychopathological antecedents, suggesting that, in many patients, psychopathology develops after FM. To conclude, we confirm the emotional suffering undergone by most people with FM, and the psychologist's importance in the multi disciplinary treatment of this disease. Beyond the debate about whether psychopathological symptoms are the cause or the effect of FM, empirical evidence reveals a high level of psychopathological symptoms (especially somatization, obsession-compulsion, anxiety, and depression) in a large part of the people with FM, which allows us to emphasize the great support that mental health professionals can provide to these patients. The study has important implications for the treatment of FM. [ABSTRACT FROM AUTHOR]