Inclusion and exclusion criteria
| Inclusion criteria | Exclusion criteria | |
|---|---|---|
| Patients with chronic fatigue | Persisting or constantly relapsing fatigue lasting 3 months or more | Another current disease process or demanding life event that might explain the fatigue |
| Functional disability resulting from fatigue that prevents normal school attendance | Another chronic disease | |
| Age ≥12 and <18 years | Permanent use of drugs (including hormones) possibly interfering with measurements Permanently bed-ridden Positive pregnancy test Pheocromocytoma Evidence of reduced cerebral and/or peripheral circulation due to vessel disease Polyneuropathy Renal insufficiency Known hypersensitivity towards clonidine or inert substances (lactose, sucrose) in capsula Abnormal ECG (apart from ectopic beats) Supine heart rate <50 bpm Supine systolic blood pressure <85 mm Hg Upright systolic blood pressure fall >30 mm Hg | |
| Healthy control subjects | Age ≥12 and <18 years | Another chronic disease Permanent use of drugs (including hormones) |