Hypothesis: Computer controlled continuous positive airway pressure (autoCPAP) is equally effective in improving obstructive sleep apnea syndrome symptoms, breathing disturbances, objective vigilance, and it is cost-effective compared to conventional fixed continuous positive airway pressure.

1. To investigate whether computer controlled continuous positive airway pressure (autoCPAP) improves subjective sleepiness, quality of life, objective vigilance, and nocturnal respiration to a similar degree as conventional fixed continuous positive airway pressure in the initial phase of treatment and over the subsequent 2 years during home therapy
2. To investigate the cost of autoCPAP compared to fixed CPAP therapy

Inclusion Criteria:

• Excessive sleepiness, and Epworth Sleepiness Score > or = 8
• Apnea- Hypopnea-Index (AHI) > or = 10/hour
• Age 18-75

Exclusion Criteria:

• Psychophysiological incapacity to perform questionnaires
• Other sleep disorders
• Psychiatric disease requiring treatment
• Previous CPAP therapy
• Previous uvulopalatopharyngoplasty
• Chronic nasal obstruction that required treatment for more than 1 month
• Cancer
• COPD, with FEV1 < 50% predicted
• Symptomatic cardiovascular disease requiring treatment defined as congestive heart failure > NYHA II
• Previous stroke with neurological residuum
• Cheyne-Stokes respiration
• Chronic pain syndromes, fibromyalgia
• Drug or alcohol addiction