[Prevalence and comorbidity of sleep disorders in general population]

Sleep disorders can be expressed in different ways. The International Classification of Sleep Disorders lists more than 80 different sleep disorder diagnoses. In general population, although the insomnia complaint is reported by nearly the third of the population, it is translated into a diagnosis of insomnia for only 6% to 15% of the population. Sleep apnea syndrome, often associated with insomnia or daytime sleepiness, is found in approximately 2% to 4% of the general population. Restless legs syndrome is present for approximately 6% of the general population with a higher prevalence in the elderly subject. Narcolepsy is rare with a prevalence of 0.04%. Parasomnias are less studied in the general population; prevalences of several of parasomnias remain unknown. Among those more extensively studied, sleep paralysis is found for approximately 6% of the general population. Nocturnal terrors, the confusional arousals and nightmares have been observed with prevalences ranging from 2.2% to 5%. Despite their high frequency, sleep disorders remain poorly identified; less than 20% of individuals with sleep disorders are correctly diagnosed and treated.