1. Department of Psychiatry, University Hospital of Heraklion, Heraklion, Crete, Greece
2. Sleep Research and Treatment Center, Department of Psychiatry, Penn State University, Hershey, PA, USA
3. Department of Neurology, University Hospital of Heraklion, Heraklion, Crete, Greece
4. Department of Internal Medicine, University Hospital of Heraklion, Heraklion, Crete, Greece