title: Type D personality is associated with sleep problems in adolescents. Results from a population-based cohort study of Swedish adolescents.
abstract: OBJECTIVE
  Sleep problems are associated with an increased risk of psychiatric and somatic diseases. Type D personality, or the distressed personality, refers to the joint tendency to experience negative emotions and to inhibit self-expression in social interaction. Type D personality is associated with an increased number of health complaints including cardiovascular diseases. The present study investigated whether type D personality was associated with sleep problems among adolescents.
  
  
  METHODS
  The study was part of the Survey of Adolescent Life in Västmanland 2008 (SALVe 2008). A total of 5012 adolescents (age 15-18 years old) completed a questionnaire including the type D measurement DS14 and questions on sleep disturbances, sleep hours during school nights, and sleep hours during weekend nights.
  
  
  RESULTS
  Adolescents with a type D personality had an approximately four times increased risk of having sleep disturbances. Moreover, type D personality was associated with sleeping fewer hours.
  
  
  CONCLUSIONS
  As adolescence represents a formative period for development it is critical to identify sleep disorders early. The presence of type D personality associated with poor sleep demands attention because sleep problems may be an early stage in the development of later diseases.
authors.affiliation: Centre for Clinical Research, Uppsala University, Central Hospital, Västerås, Sweden. emelie.conden@ltv.se
authors.forename: Emelie
authors.initials: E
authors.lastname: Condén
authors.forename: Lisa
authors.initials: L
authors.lastname: Ekselius
authors.forename: Cecilia
authors.initials: C
authors.lastname: Aslund
mesh_terms: D000293:Adolescent; D015331:Cohort Studies; D003863:Depression / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D010551:Personality / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000523:psychology*; D011795:Surveys and Questionnaires; D013548:Sweden