1. Department of Medical Sciences and Public Health, Sleep Disorder Research Center, University of Cagliari, 09124 Cagliari, Italy
2. Sleep Outpatient Service, Clinica Tommasini di Jerzu, 08044 Jerzu, Italy
3. Department of Medical Sciences and Public Health, Section of Psychiatry, University of Cagliari, 09124 Cagliari, Italy
4. University Hospital of Cagliari, 09042 Cagliari, Italy