Psychiatric status among stepchildren and domestic and international adoptees in Denmark. A comparative nationwide register-based study.
OBJECTIVE
To investigate adoptees' psychiatric contact compared with non-adoptees and to clarify the related diagnoses.


METHODS
Observational, nationwide, register-based study, where correlations between psychiatric, demographic and socioeconomic variables were analyzed for adoptees compared with non-adoptees. The study period is 1992-2008. The setting is Denmark, encompassing seven different types of adoptees registered from 1988 to 2005 (n = 13,524). The non-adoptees (n = 839,989) are matched on sex, age and residence. Various comparison models are designed: one with delayed entries (17 years) shows a 5.0% psychiatric contact prevalence for non-adoptees and 9.2% for adoptees (adjusted odds ratio: 2.91). Another design without delayed entries (2 years) shows a 2% prevalence for non-adoptees and 3.9% for adoptees (adjusted odds ratio 2.65). p-values <0.0005.


RESULTS
Only one type of adoptee: ''registered partner's adoption of the other partner's child'' has a lower risk than non-adoptees (odds ratio: 0.26). Comparison within the same birth region shows a significant increased risk for most adoption types. More adoptees than non-adoptees have more than one contact. Age at adoption is an additional risk factor for4one year only. The most frequent diagnosis is ''Inherent or acquired brain suffering'' (ICD-10: F50 - F99).


CONCLUSIONS
The results stress that ''adoptee'' is an independent risk factor for psychiatric contact for international as well as for Danish adoptees. Danish stepchildren have a higher risk than non-adopted Danish children, while ''registered partner's child adopted by the other partner'' have a lower risk than non-adopted Danish children.
Laubjerg
Merete
M
University of Copenhagen, Institute of Public Health, Section of General Practice, Unit of Women and Gender Research in Medicine, Copenhagen, Denmark. mela@pubhealth.ku.dk
Christensen
Anne Maj
AM
Petersson
Birgit
B
D000293:Adolescent; D000300:Adoption / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D008603:Mental Health; D011569:Psychiatric Status Rating Scales; D002666:Psychology, Child; D012042:Registries; D012307:Risk Factors; D015406:Single Parent; D012959:Socioeconomic Factors; D055815:Young Adult