<unk>  is experienced equally in males and females. Lifetime prevalence rates derived from 35 aggregated studies indicate that approximately 8% of the general population, 28% of students, and 32% of psychiatric patients experience at least one episode of<unk>  at some point in their lives. Rates of recurrent<unk>  are not as well known, but 15%-45% of those with a lifetime history of<unk>  may meet diagnostic criteria for Recurrent Isolated<unk> . In surveys from Canada, China, England, Japan and Nigeria, 20% to 60% of individuals reported having experienced<unk>  at least once in their lifetime. In general, non-whites appear to experience<unk>  at higher rates than whites, but the magnitude of the difference is rather small. Approximately 36% of the general population that experiences isolated<unk>  is likely to develop it between 25 and 44 years of age. Isolated<unk>  is commonly seen in patients that have been diagnosed with narcolepsy. Approximately 30–50% of people that have been diagnosed with narcolepsy have experienced<unk>  as an auxiliary symptom. A majority of the individuals who have experienced<unk>  have<unk> oradic episodes that occur once a month to once a year. Only 3% of individuals experiencing<unk>  that is not associated with a neuromuscular disorder have nightly episodes.
Sleep paralysis
Narcolepsy
Sedation
Night terror
Sleep disorder
Hypokalemic periodic paralysis
Syncope 
Atonic seizure