Table 1

Inclusion and exclusion criteria

Inclusion criteriaExclusion criteria
Patients with chronic fatiguePersisting or constantly relapsing fatigue lasting 3 months or moreAnother current disease process or demanding life event that might explain the fatigue
Functional disability resulting from fatigue that prevents normal school attendanceAnother chronic disease
Age ≥12 and <18 yearsPermanent use of drugs (including hormones) possibly interfering with measurements
Permanently bed-ridden
Positive pregnancy test
Evidence of reduced cerebral and/or peripheral circulation due to vessel disease
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 subjectsAge ≥12 and <18 yearsAnother chronic disease
Permanent use of drugs (including hormones)