title: The clinical significance of preschool depression: impairment in functioning and clinical markers of the disorder.
abstract: OBJECTIVE
  While much is now known about depression during school age and adolescence, whether clinical depression can onset even earlier in development during the preschool period remains under explored. The earliest possible identification of depression may be important for the design of prevention and early developmental intervention programs. This study investigated functional impairment associated with depression, symptoms that served as the best markers of depression vs. other disorders, as well as depression severity between two depressed sub-groups and other diagnostic comparison groups.
  
  
  METHODS
  Three hundred and five preschoolers between the ages of 3.0 and 6.0 and their primary caregivers were recruited using a depression screening checklist distributed at community sites. The Preschool Age Psychiatric Assessment (PAPA) was used to derive psychiatric diagnoses in the study sample. Multivariate analyses of covariance were used to investigate the effects of depression on independent measures of functional impairment while controlling for the effects of co-morbidities.
  
  
  RESULTS
  Functional impairment specifically associated with depression was found in multiple domains and contexts, however depressed preschoolers were not developmentally delayed. The symptoms of guilt and extreme fatigue were found to be highly specific for preschool depression. A statistically significant hierarchy of depression severity was found between diagnostic comparison groups, in the expected direction with the highest in a melancholic subgroup.
  
  
  CONCLUSIONS
  Validation for preschool depression with associated functional impairment across contexts was found in preschool children. These findings replicate and extend earlier evidence for validity of MDD diagnosed in the preschool period and highlight the need for clinical attention. The finding that these depressed and impaired preschoolers were not yet developmentally delayed may have important public health significant significance as it suggests a possible window of opportunity for early intervention. Study findings were limited by reliance on parent and teacher informants and a cross-sectional view.
authors.affiliation: Washington University School of Medicine, Department of Psychiatry, Box 8134, 660 S. Euclid, St. Louis, MO 63110, United States. lubyj@psychiatry.wustl.edu
authors.forename: Joan L
authors.initials: JL
authors.lastname: Luby
authors.forename: Andy C
authors.initials: AC
authors.lastname: Belden
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pautsch
authors.forename: Xuemei
authors.initials: X
authors.lastname: Si
authors.forename: Edward
authors.initials: E
authors.lastname: Spitznagel
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D017028:Caregivers / Q000523:psychology / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool / Q000706:statistics & numerical data*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000706:statistics & numerical data; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D002658:Developmental Disabilities / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005221:Fatigue / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006167:Guilt; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010555:Personality Inventory / Q000706:statistics & numerical data; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires