Adoptees' responses to separation from, and reunion with, their adoptive parent at age 4 years is associated with long-term persistence of autism symptoms following early severe institutional deprivation.

Institutionally deprived young children often display distinctive patterns of attachment, classified as insecure/other (INS/OTH), with their adoptive parents. The associations between INS/OTH and developmental trajectories of mental health and neurodevelopmental symptoms were examined. Age 4 attachment status was determined for 97 Romanian adoptees exposed to up to 24 months of deprivation in Romanian orphanages and 49 nondeprived UK adoptees. Autism, inattention/overactivity and disinhibited-social-engagement symptoms, emotional problems, and IQ were measured at 4, 6, 11, and 15 years and in young adulthood. Romanian adoptees with over 6 months deprivation (Rom>6) were more often classified as INS/OTH than UK and Romanian adoptees with less than 6 months deprivation combined. INS/OTH was associated with cognitive impairment at age 4 years. The interaction between deprivation, attachment status, and age for autism spectrum disorder assessment was significant, with greater symptom persistence in Rom>6 INS/OTH(+) than other groups. This effect was reduced when IQ at age 4 was controlled for. Age 4 INS/OTH in Rom>6 was associated with worse autism spectrum disorder outcomes up to two decades later. Its association with cognitive impairment at age 4 is consistent with INS/OTH being an early marker of this negative developmental trajectory, rather than its cause.