Sleep disorder, Mediterranean Diet and learning performance among nursing students: inSOMNIA, a cross-sectional study.

The International Classification of Sleep disorders, the International Classification of Diseases and the Diagnostic and Statistical manual of Mental Disorders defines insomnia as an experience of insufficient or poor sleep quality, characterized by at least one of the following symptoms: difficulty in initiating or maintaining sleep, early awakenings and poor restorative sleep. In Italy, the Morfeo 1 study detects a prevalence of 20% of insomnia and a 40% of cases with day-time symptoms. The chronic sleep deprivation is responsible for cognitive disorders with effects on social life. Being common knowledge, lifestyle can also influence sleep. Some of the "sleep hygiene rules" involve a control on smoking, coffee consumption and diet. The Mediterranean Diet (MD), thanks to its high level of tryptophan, has a positive influence on sleep and can protect against stress and anxiety.