The health impacts of adoption have not been studied by the population health field in the United States, in part because we have never tracked or officially counted adoptees in the general population through official records such as the U.S. Census, until 2000 (a limited count began that year). I explain some of the reasons for failing to count adoptees in a separate article. Denmark does have a reliable adoption registry, which enabled one of the best population studies to be released on long-term health outcomes for adoptees.
Mental health and behavioral health researchers have made many studies, often with limitations for millions of adoptees because of research methods that make them unreliable predictors of actual outcomes for most adoptees. My forthcoming book attempts to show that adoption must be viewed through a public health lens and that medical and health professionals have a moral obligation to promote equal rights for adoptees, to ensure millions of Americans have better health.
Petersen, Lisette, Thorkild I.A. Sørensen, Erik Lykke Mortensen, and Per Kragh Andersen. “Excess Mortality Rate During Adulthood Among Danish Adoptees,” PLOS ONE 5 no. 12 (2010): http://dx.doi.org/10.1371/journal.pone.0014365.
This population health based study found adoptees have an increased all-cause mortality compared to the general population. The authors also found all major specific causes of death contributed to this outcome, with the highest excess seen for alcohol-related deaths.
The Adoption History Project, Psychopathology Studies:
The Adoption History Project, at the University of Oregon, has compiled a list of studies attempting to prove or disprove that adoption impacts the mental and emotional health of children, making them prone to developmental, behavioral, and academic problems. Most were not rigorous in methods, sample sizes, or applicability to the millions of adoptees in the United States. However, the project concludes, “Most Americans agree that adoption is a ‘risk factor,’ according to public opinion polls.”