Chronic fatigue syndrome (ME/CFS) is a severe medical condition. It is characterized by long term fatique and other persisted symptoms, such as a cognitive disabilities and orthostatic intolerance. Symptoms limit a persons ability to carry out ordinary daily activities. In ICD- 10, disease is known as G93.3, postviral fatigue syndrome.

The purpose of this research (doctoral study) is to produce a health psychological group intervention for patients with ME/CFS.

Research protocol: 70-80 patients with diagnosis G 93.3. Psychological and psychiatric evaluation for patients (SCID I and parts from SCID II). Depression diagnosis is allowed (on remission). Medication for depression is also allowed. Measurements for ortostatic intolerance (Somnotouch nimbTM) and laboratory measurements: complete blood count, CRP, alkaline phosphatase, GT, ALAT, CK, bilirubin, kidney and thyroid (TSH, T4V) function tests, serum ferritin, glucose, electrolytes and daily urine sodium excretion.

Autonomic nervous system ganglio antibodies: Anti-AT1R- Antibodies, Anti- ETAR- Antibodies, anti alpha-1 adrenergic Receptor Antibodies, anti alpha 2 adrenergic Receptor Antibodies, anti beta-1 adrenergic Receptor Antibodies, anti beta-2-adrenergic Receptor Antibodies, anti- Muscarinic Cholinergic Receptor 1 (M1)- Antibodies, anti- Muscarinic Cholinergic Receptor 2 (M2)- Antibodies, anti- Muscarinic Cholinergic Receptor 3 (M3)- Antibodies, anti- Muscarinic Cholinergic Receptor 4 (M4)- Antibodies, anti- Muscarinic Cholinergic Receptor 5 (M5)- Antibodies.

Testing and inventories before rehabilitation/ at the end of the rehabilitation and 3 months follow-up.

1. ME/CFS patients modalities of agency.The study includes five patients with chronic fatigue syndrome and examines their modalities of agency. A special focus is on the effects of the health care system on the patients' agency.The research is qualitative, the data was analyzed using theory-driven content analysis.
2. The study explores the experiences of Health Psychological group rehabilitation for patients with ME/CFS. The aim is to better overall functioning and management of illness through goal-oriented work, dealing emotions with the crisis of the illness, adopting, and implementing healthy lifestyle choices. The study is qualitative (n=10) using content analysis.
3. Randomized controlled research. n=70. Treatment/research group n=35. Control- group (35) participates on health counselling (6 sessions). Research question: is health psychological group rehabilitation clinically statistically significant. Comparison is between research- and control groups but also between patients who are diagnosed 93.3, having also objective impairment in cognitive functions or orthostatic intolerance, comparing to patients only diagnosed on G93.3.

Inclusion Criteria:

• Clinical diagnosis of Chronic fatigue syndrome, G 93.3
• Must be able to sit two hours and do homework tasks
• Must be motivated to co-operate with other patients
• Goal oritentation
• Have an interest to learn health psychological approach and willingness to participate rehabilitation

Exclusion Criteria (diseases without treatment/ acute phase):

• hypothyroidism
• sleep apnea or narcolepsy
• major depressive disorders, bipolar affective disorders, schizophrenia
• eating disorders
• cancer
• autoimmune disease
• hormonal disorders
• subacute infections
• obesity
• alcohol or substance abuse
• vitamin D deficiency