This study is based on clinical findings that some patients with fibromyalgia have a tendency towards lower levels of the stress hormone cortisol. The hypothesis to be tested in this study is that the administration of a very low-dose of cortisol which has no side effects corrects this deficiency and results in an improvement of symptoms

Fibromyalgia (FMS) is regarded as one of the most important chronic pain syndromes with a high prevalence in the general population.

Hypotheses to be tested in this study:

• Impaired glucocorticoid signaling is associated in a failure to terminate the chronic stress response seen in patients with FMS.
• Low-dose hydrocortisone in patients with FMS results in a reduction in pain and other stress-related symptoms of FMS

Intervention:

2 x 5 mg of hydrocortisone given at noon and in the evening

Study design:

Double-blind, randomized, cross-over, within-subject

Presumed mechanism of main hydrocortisone effect:

• Improvements in FMS symptoms representing (functional) hypocortisolism
• Increased pain threshold

Expected results:

• Moderate reductions in physical impairment, fatigue, and stiffness
• Improvements in sleep quality
• Decline in pain intensity Inclusion criteria
• FMS diagnosis according to the American College of Rheumatology 1990 Criteria
• Age between 18 and 60 years

Exclusion criteria

• Disease states representing contraindications to the administration of glucocorticoids (tuberculosis, gastric- and duodenal ulcers, Cushing's disease, osteoporosis, hypertension, pregnancy and lactation, psychosis, glaucoma, diabetes mellitus, thrombophilia, active or chronic bacterial or viral infections, hypothyreosis, cirrhosis).
• Severe or chronic somatic diseases.
• Psychiatric diseases according to DSM-IV (except PTSD, minor depressive episodes, minor personality disorders).
• Body weight >20% above or below normal.
• Changes in pharmacologic or psychotherapeutic management less than 3 months ago.
• Age < 18 years

Proposed outcome measures

• Primary: FMS symptoms, pain scores, tenderness at tender points
• Secondary: Chronic stress symptoms, health-related quality of life

Possible benefit and use of data from the trial

This trial could help to identify glucocorticoid resistance as a major mechanism underlying the sustained stress - reactions seen in FMS and establish low-dose hydrocortisone as a useful drug for treatment of stress-related disorders.

Inclusion Criteria:

• FMS diagnosis according to the American College of Rheumatology 1990 Criteria.
• Age between 18 and 60 years

Exclusion Criteria:

• Disease states representing contraindications to the administration of glucocorticoids (tuberculosis, gastric- and duodenal ulcers, Cushing's disease, osteoporosis, hypertension, pregnancy and lactation, psychosis, glaucoma, diabetes mellitus, thrombophilia, active or chronic bacterial or viral infections, hypothyreosis, cirrhosis)
• Severe or chronic somatic diseases
• Psychiatric diseases according to DSM-IV (except PTSD, minor depressive episodes, minor personality disorders)
• Body weight >20% above or below normal
• Changes in pharmacologic or psychotherapeutic management less than 3 months ago
• Age < 18 years