title: Mental Health in Internationally Adopted Adolescents: A Meta-Analysis.
abstract: OBJECTIVE
  To investigate whether mental health problems differ between internationally adopted adolescents and their non-adopted peers and examine design and sample characteristics that might underlie differences among studies.
  
  
  METHODS
  Studies published through August 2015 were collected through Embase, Medline, PsychINFO, Web of Science, ERIC, and Svemed+. Combined effect estimates were calculated using random-effects models.
  
  
  RESULTS
  Eleven studies investigating 17,919 adoptees and 1,090,289 non-adopted peers were included in the meta-analysis. Internationally adopted adolescents reported more mental health problems across domains than their peers, with effect estimates (standardized mean differences [SMDs]) of 0.16 (95% CI 0.03 to 0.28) for questionnaire-based studies and 0.70 (95% CI 0.50 to 0.90) for register-based studies. They also reported significantly more externalizing difficulties (SMD 0.20, 95% CI 0.03 to 0.38), although the effect estimate for internalizing difficulties was not statistically significant (SMD 0.10, 95% CI -0.03 to 0.24). Studies using categorical measurements of mental health problems, indicating more serious problems, yielded larger effect estimates than continuous measurements (SMD 0.31, 95% CI 0.21 to 0.41; SMD 0.13, 95% CI -0.01 to 0.26, respectively). The difference in mental health problems between international adoptees and their peers was somewhat larger when using parent report compared with self-report. More recent studies (conducted in 1995 and later) yielded larger estimates than older studies, although no significant difference was found for this analysis or subgroup analyses investigating sex and age at adoption.
  
  
  CONCLUSIONS
  Although most internationally adopted adolescents are well adjusted, adoptees as a group report higher levels of mental health problems compared with non-adopted peers. This difference should be acknowledged and adequate support services should be made available.
authors.affiliation: Norwegian Institute of Public Health, Bergen and the Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health. Electronic address: kristin.gartner.askeland@fhi.no.
authors.forename: Kristin Gärtner
authors.initials: KG
authors.lastname: Askeland
authors.affiliation: Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health.
authors.forename: Mari
authors.initials: M
authors.lastname: Hysing
authors.affiliation: University of Miami.
authors.forename: Annette M
authors.initials: AM
authors.lastname: La Greca
authors.affiliation: Norwegian Institute of Public Health.
authors.forename: Leif Edvard
authors.initials: LE
authors.lastname: Aarø
authors.affiliation: University of Bergen, Bergen, Norway.
authors.forename: Grethe S
authors.initials: GS
authors.lastname: Tell
authors.affiliation: Norwegian Institute of Public Health, Bergen and the Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research Health; Helse Fonna, Haugesund, Norway.
authors.forename: Børge
authors.initials: B
authors.lastname: Sivertsen
mesh_terms: D000293:Adolescent; D000300:Adoption; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology*
keywords: adolescence; adoption; mental health; meta-analysis