Cognitive Behavioral Therapy Trial in Fibromyalgia

Long-lasting pain is a common cause for disability. In several studies 30-40% of the adult general population suffer from pain. In this group of subjects the fibromyalgia syndrome (FMS) is common,. This is a well defined disorder with generalized pain, well defined tenderpoints according to the American Collage of Rheumatology (ACR) criteria, and a number of other associated symptoms. About 5-10% of the general female population suffers from fibromyalgia. The disorder is infrequent among men.

The etiology of the condition is unknown. However, a multi-factorial origin is postulated, where some form of stress is a contributing factor. Also neuro-endocrine disturbances have been observed. Cognitive behavioral therapy CBT) is an evidence based efficient treatment method in depression and panic disorder. In open studies it has proved to be an effective stress and pain reducer.

The purpose of the trial was to evaluate the effect of CBT in a group of female FMS patients regarding pain, stress, and well-being (outcome). A purpose was also to study mediating factors, such as biological markers for stress and pain, and psycho-social factors.

The study population consisted of 48 women, 27-62 years of age, living in Östhammar municipality, central Sweden, with a verified FMS according to the 1992 ACR criteria, and no other serious disorder. The were recruited by advertising in the local printed press and meetings with the local rheumatology patient association.

54 subjects were screened for participation. A physical examination was performed, a medical history was taken, blood samples and saliva specimens for biological markers regarding metabolic status, pain and stress were taken, and a questionnaire was filled out. 48 women fulfilled the inclusion criteria and gave informed consent to participation. A randomized block design was used by which the women were randomly allocated to two groups, an early treatment group and a waiting list group.

The early treatment group was subdivided into four treatment groups with six participants in each. The CBT treatment was given by certified therapists and supervised by the chief therapist, an experienced psychologist. Each group had the same therapist throughout the trial. The therapy was given as group sessions once a week for 20 weeks. When the therapy was completed the outcome variables were measured by means of questionnaire, and the same blood and saliva specimens as at baseline were taken. During the next six months two booster CBT sessions were performed. One year after baseline a final follow-up evaluation was made.

The waiting list group served as reference (or control) group to the early treatment group during the first six months from baseline. No CBT therapy was given, but otherwise exactly the same procedure was followed. When the control period was over the waiting list group got their CBT treatment and evaluations following the same protocol as the early treatment group.

The outcome evaluation are based on a number of questionnaire instruments, such as the Multidimensional Pain Inventory (MPI), the Type A behavior instrument (Everyday stress), The Maastricht Questionnaire ("Vital exhaustion"), and the self administered Montgomery Åsberg Depression Rating Scale (MADRS-S) instrument. The blood sampling aimed at analyzing the neuro-peptides substance P, Met-Enkephalin-Arginine-Phenylalanine (MEAP), beta-endorphin, and neuro-peptide Y, in addition to estrogen, testosterone, prolactin and dehydroepiandrosterone (DHEA). The saliva specimens were intended to measure diurnal variation of cortisol. To standardize the hormonal level all evaluations were done in ovulation phase of the menstrual cycle.