Self-reported mental health of children known to child protection services: an Australian population-based record linkage study.

Maltreated children are vulnerable to adverse mental health outcomes. Information about how children's mental health needs vary according to different levels of child protection contact (potentially culminating in out-of-home care [OOHC]) is valuable for the effective provision of services. This study aimed to examine associations between different levels of contact with child protection services before the age of 10 years and self-reported mental health difficulties at age 11 years. Participants (n = 26,960) were drawn from the New South Wales Child Development Study, a multiagency, multigenerational, longitudinal record linkage study that combines administrative records with cross-sectional survey data. We examined associations between four levels of child protection response (non-threshold reports, unsubstantiated reports, substantiated reports, OOHC; each relative to no report) and six domains of self-reported mental health difficulties (including internalising and externalising symptoms, and psychotic-like experiences). All levels of contact with child protection services were associated with increased odds of mental health difficulties in all domains. Children who had been placed in OOHC and children with substantiated reports had the highest odds of reporting clinical levels of mental health difficulties; 48.1% of children with an OOHC placement and 45.6% of those with substantiated child protection reports showed clinical levels of mental health difficulties in at least one domain. Children with child protection reports that were unsubstantiated, or determined not to meet the threshold for risk-of-significant harm, were also at increased risk of mental health difficulties in middle childhood. These findings underscore the importance of early detection and intervention for all children at risk of maltreatment.