Population-based studies suggest that about
30 per cent of the general population complains of
sleep disruption, while approximately 10 per cent
has associated symptoms of daytime functional
impairment consistent with the diagnosis of insomnia,
though it is unclear what proportion of that 10 per cent
suffers from chronic insomnia. Not surprisingly, higher
prevalence rates are found in clinical practices, where
about one-half of respondentsreportsymptoms ofsleep
disruption.