title: The use of symptom dimensions to investigate the longitudinal effects of life events on depressive and anxiety symptomatology.
abstract: BACKGROUND
  Findings on the association between life events and depression have been quite inconsistent. This could be due to the heterogeneity of traditionally used depression outcomes. The aim of this study was to investigate whether specific symptom dimensions can be used as an alternative to detect more specific life event effects.
  
  
  METHODS
  Participants with/without psychiatric diagnoses were included (n=2252). Dimensions of the tripartite model (General Distress [GD], Anhedonic Depression [AD] and Anxious Arousal [AA]) were assessed at baseline, 1-year and 2-year follow-up. Life events occurring between measurements were assessed retrospectively. Longitudinal associations between life events and dimensional scores were analysed with Linear Mixed Models.
  
  
  RESULTS
  Occurrence of negative life events was associated with increasing GD and AA, and less with AD. Positive life events were associated with decreasing GD and AD, but not with AA. The association between negative life events and AD was larger in the absence of previous psychiatric problems, lending support to a dimension-specific 'kindling' effect. Also, the negative association between negative life events and GD was stronger in those with high neuroticism. Multivariable analyses with individual life events showed that a few strong independent effects remained for each dimension.
  
  
  CONCLUSIONS
  Life event reports were retrospective; only three outcome dimensions were used.
  
  
  CONCLUSIONS
  These results show that the effects of life events and modifying factors depend, to an extent, on the symptom domain that is considered as outcome, illustrating the need to account for symptom heterogeneity in etiological life event research.
authors.affiliation: University of Groningen, University Medical Center Groningen, Interdisciplinary Center Psychopathology and Emotion regulation (CC-72), PO Box 30.001, 9700 RB Groningen, The Netherlands. Electronic address: k.j.wardenaar@umcg.nl.
authors.forename: Klaas J
authors.initials: KJ
authors.lastname: Wardenaar
authors.affiliation: Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Tineke
authors.initials: T
authors.lastname: van Veen
authors.affiliation: Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Giltay
authors.affiliation: Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Frans G
authors.initials: FG
authors.lastname: Zitman
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands; Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands; Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Brenda W J H
authors.initials: BW
authors.lastname: Penninx
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D008016:Life Change Events; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D012189:Retrospective Studies; D055815:Young Adult
keywords: Depression; Dimensions; General distress; Life events; Tripartite