Functional connectivity of youth in family-like residential care in Japan: Impact of reactive attachment disorder and disinhibited social engagement disorder symptoms

Adverse childhood experiences are a risk factor for attachment disorders. While several neuroimaging studies have shown changes in functional networks in children who have experienced institutional care, the results are inconsistent. Furthermore, no research has been conducted on how structured residential care, such as Japan's small-group family-style care, influences attachment-related symptoms and functional connectivity. This study compared attachment-related symptoms (reactive attachment disorder [RAD] and disinhibited social engagement disorder [DSED] symptoms) between youth aged 9-18 years raised in Japanese small-group residential care (RC; n = 31) and those raised in birth families but not in RC (NRC; n = 37). Group differences in resting-state functional connectivity were also analyzed using multivariate pattern analysis (MVPA) on functional magnetic resonance imaging (fMRI) data. MVPA revealed group differences in whole-brain functional connectivity patterns from the right occipital pole and the left lingual gyrus (LLG). Functional connectivity between the LLG and the frontal medial cortex (FMC) was reduced in RC youth. LLG-FMC connectivity was positively correlated with RAD scores, while longer duration of stay in RC was negatively correlated with RAD symptoms. This study highlights caregiving environment's influence on attachment-related symptoms and functional connectivity, higher levels of RAD and DSED symptoms and reduced LLG-FMC functional connectivity in the RC group. However, this study further demonstrated not only the association between longer stays in family-like RC and the reduction of RAD symptoms but also changes in the connectivity. These findings suggest that stable, high-quality care may have the potential to mitigate adverse developmental outcomes.