The ERA study investigated the outcomes of children adopted into the United Kingdom from Romania in the late 1980s. Participants were adopted from Romania into families resident in England, aged less than 4 years at the time of entry to the United Kingdom and processed by the United Kingdom Home Office or the United Kingdom Department of Health and Social Care. Participants were divided into two groups. The institution-reared group included participants who had resided in an institution in Romania for more than two weeks before adoption. The family-reared group was comprised of participants who had spent no more than two weeks in an institution before adoption. At baseline, the ERA study included 165 Romanian children. A control group of 52 children who were adopted within the United Kingdom was also included in the study.