Behavior problems and mental health referrals of international adoptees: a meta-analysis

International adoption involves more than 40,000 children a year moving among more than 100 countries. Before adoption, international adoptees often experience insufficient medical care, malnutrition, maternal separation, and neglect and abuse in orphanages.

To estimate the effects of international adoption on behavioral problems and mental health referrals.

We searched MEDLINE, PsychLit, and ERIC from 1950 to January 2005 using the terms adopt* combined with (behavior) problem, disorder, (mal)adjustment, (behavioral) development, clinical or psychiatric (referral), or mental health; conducted a manual search of the references of articles, books, book chapters, and reports; and consulted experts for relevant studies. The search was not limited to English-language publications.

Studies that provided sufficient data to compute differences between adoptees (in all age ranges) and nonadopted controls were selected, resulting in 34 articles on mental health referrals and 64 articles on behavior problems.

Data on international adoption, preadoption adversity, and other moderators were extracted from each study and inserted in the program Comprehensive Meta-analysis (CMA). Effect sizes (d) for the overall differences between adoptees and controls regarding internalizing, externalizing, total behavior problems, and use of mental health services were computed. Homogeneity across studies was tested with the Q statistic.

Among 25,281 cases and 80,260 controls, adoptees (both within and between countries) presented more behavior problems, but effect sizes were small (d, 0.16-0.24). Adoptees (5092 cases) were overrepresented in mental health services and this effect size was large (d, 0.72). Among 15,790 cases and 30,450 controls, international adoptees showed more behavior problems than nonadopted controls, but effect sizes were small (d, 0.07-0.11). International adoptees showed fewer total, externalizing and internalizing behavior problems than domestic adoptees. Also, international adoptees were less often referred to mental health services (d, 0.37) than domestic adoptees (d, 0.81). International adoptees with preadoption adversity showed more total problems and externalizing problems than international adoptees without evidence of extreme deprivation.

Most international adoptees are well-adjusted although they are referred to mental health services more often than nonadopted controls. However, international adoptees present fewer behavior problems and are less often referred to mental health services than domestic adoptees.