According to a recent study conducted by researchers from the University of Minnesota, adoption is linked with a higher prevalence of mental health problems in children than in non-adopted ones. The study went as follows:
The adoption study compared a random sample of 540 adolescents born in Minnesota, who were not adopted, with a representative sample of adoptees (514 international adoptees and 178 domestic adoptees). The children had been placed by the 3 largest adoption agencies in Minnesota.3
“All of the kids were adopted within the first 2 years of life, but the great majority were adopted within the first year,” said Margaret A. Keyes, PhD, lead author of the study and a research psychologist. “The average age at placement was 4 months. So it is not as if you are looking at 3- and 4-year-olds coming over on a plane from a faraway country.”
At the time of the assessments, the study participants ranged in age from 11 to 21 years. The assessments were rigorous and involved use of the Diagnostic Interview for Children and Adolescents-Revised (DICA-R) and the Structured Clinical Interview for DSM-III-R (SCID-II). (Both had been updated to cover DSM-IV criteria.) The modified DICA-R was also administered to mothers of participants to assess disorders in their children (Kaplan, 2009).
The study was notable as "one of the first to investigate the prevalence of common DSM-IV childhood disorders in a population-based sample of adopted adolescents"(Kaplan, 2009). The DSM disorders studied in particular included oppositional defiant disorder (ODD), ADHD, separation anxiety disorder, major depressive disorder and conduct disorder (Kaplan, 2009). The results suggested a notable correlation between being adopted and exhibiting mental health problems:
The odds of having ADHD or ODD were about twice as high in all adopted adolescents. For example, Keyes said, 7 to 8 out of 100 nonadopted adolescents had ADHD compared with 14 to 15 out of 100 of the adoptees. In addition, domestic adoptees had higher odds of having conduct disorder than nonadopted adolescents. Consistent with a meta-analysis by Juffer and van Ijzendoorn,4 the University of Minnesota researchers found that international adoptees had fewer externalizing behavioral problems than domestic adoptees. This finding is somewhat provocative, because some researchers5 have speculated that international adoptees would be at increased risk for mental health problems because they are more likely to have been placed in the adoptive home at a later age, to have experienced preplacement adversity, or to have been exposed to postplacement discrimination.
In contrast, Juffer and van Ijzendoorn (authors of the meta-analysis) suggested that adoptive parents of international adoptees may be better prepared to rear an adopted child than the adoptive parents of domestic adoptees. They also suggested that domestic adoptees may experience greater prenatal exposure to teratogenic substances or have a greater genetic risk for mental health problems than international adoptees.
International adoptees were significantly more anxious than nonadopted adolescents and, according to their parents, had significantly more symptoms of major depressive and separation anxiety disorders (Kaplan, 2009).
Nevertheless, the researchers point out that most children who are adopted as infants are psychologically healthy.
Kaplan, Arline (2009). Adoption and Mental Illness. Retrieved from: http://www.psychiatrictimes.com/articles/adoption-and-mental-illness#sth...