title: The Munich Vulnerability Study on Affective Disorders: stability of polysomnographic findings over time.
abstract: BACKGROUND
  Some of the sleep abnormalities found in depression also persist in remission, suggesting that these parameters could represent trait or vulnerability markers. In a previous study, we found that about one third of a group of high-risk probands (HRPs) showed sleep patterns that were comparable to those of depressed patients. In the present study, we re-investigated a subsample of these HRPs to evaluate the stability of these findings over time.
  
  
  METHODS
  We investigated the sleep-electroencephalograms of 82 healthy subjects with a high genetic load of affective disorders. We were able to re-investigate 26 of these HRPs after a mean interval of 3.5 years. Thirty-five unrelated control probands and 33 unrelated depressed inpatients that were recruited at the first investigation served as reference groups.
  
  
  RESULTS
  At index investigation, we found that the HRPs showed a significantly increased rapid eye movement (REM) sleep density compared to control subjects. At the second examination, no changes of the polysomnographic observations over time could be observed; in particular, the REM density remained elevated.
  
  
  CONCLUSIONS
  The increased REM density in high-risk subjects for an affective disorder at index investigation was stable over time, so that one of the requirements for a true vulnerability marker is fulfilled.
authors.affiliation: Max Planck Institute of Psychiatry, Munich, Germany
authors.forename: Sieglinde
authors.initials: S
authors.lastname: Modell
authors.forename: Marcus
authors.initials: M
authors.lastname: Ising
authors.forename: Florian
authors.initials: F
authors.lastname: Holsboer
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Lauer
mesh_terms: D000328:Adult; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000235:genetics / Q000503:physiopathology*; D017286:Polysomnography; D015203:Reproducibility of Results; D012890:Sleep / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology