Effects of state and trait anxiety on sleep structure: A polysomnographic study in 1083 subjects.

Anxiety affects millions of people and has been shown to co-occur in combination with sleep disturbances, generating heavy medical costs and a huge socio-medico-economic burden. Sleep-studies in anxiety disorders are inconsistent and the effects of state and trait anxiety are unexplored. We selected 1083 patients from the database of a hospital sleep laboratory. The patients had polysomnography for different sleep disorders; their sleep initiation (sleep onset latency), sleep maintenance (total sleep time), non-rapid eye movement sleep-, and rapid eye movement sleep parameters; as well as their State-Trait Anxiety Inventory and Beck depression scale were measured. In order to be included in our study, individuals needed to score in the low or high range on the State and/or Trait Subscales of the State-Trait Anxiety Inventory. We found that both state and trait anxiety affected non-rapid eye movement sleep parameters. Sleep onset latency changes predominantly associated to state anxiety while rapid eye movement parameters related to trait anxiety.