title: Subthreshold depression in children and adolescents - a systematic review.
abstract: BACKGROUND
  Depressive disorders are disabling conditions striking at all ages. In adults, subthreshold depression (SD) is viewed as being on a continuum with major depressive disorder (MDD). Whether this holds for children and adolescents, is still unclear. We performed the first systematic review of SD in subjects below 18 years, in order to explore if childhood SD and MDD share causal pathways, phenomenology and outcomes, supporting a dimensional view.
  
  
  METHODS
  A critical systematic review in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. A review protocol was developed a priori, and all reports were assessed by two reviewers.
  
  
  RESULTS
  The literature search generated 941 eligible references and 24 studies were included. Although diagnostic criteria for SD showed great variability, similarities for SD and MDD were striking. Both were common conditions with similar risk factor patterns. Clinical characteristics in both groups were depressed mood, suicidal ideation and high comorbidity. Outcomes were almost equally poor, with increased psychiatric morbidity and health service use. SD intervention studies showed promising results.
  
  
  CONCLUSIONS
  Reports with data on SD not reported in keywords or abstract may have been missed by the search strategy.
  
  
  CONCLUSIONS
  A dimensional view of depressive disorders is also supported in children and adolescents, suggesting SD to be a precursor to MDD. Although SD is a somewhat milder condition than MDD, it has severe outcomes with psychopathology and impairment. There is a need of identifying cost-efficient and longlasting interventions in order to prevent development of early SD into MDD.
authors.affiliation: Department of Child and Adolescent Mental Health Odense, Research Unit (University Function), Mental Health Services in the Region of Southern Denmark, University of Southern Denmark, Odense, Denmark. rikke.wesselhoeft@rsyd.dk
authors.forename: Rikke
authors.initials: R
authors.lastname: Wesselhoeft
authors.forename: Merete J
authors.initials: MJ
authors.lastname: Sørensen
authors.forename: Einar R
authors.initials: ER
authors.lastname: Heiervang
authors.forename: Niels
authors.initials: N
authors.lastname: Bilenberg
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000523:psychology; D006801:Humans; D015995:Prevalence
keywords: Depression; Depressive disorders; Minor; Outcome; Risk factors; Subthreshold