Mental disorders in children known to child protection services during early childhood.

<bold>Objectives: </bold>To examine associations between being the subject of child protection reports in early childhood and diagnoses of mental disorders during middle childhood, by level of service response.<bold>Design, Setting, Participants: </bold>Retrospective analysis of linked New South Wales administrative data, 2001-2016, for a population cohort of children (mean age in 2016, 13.2 years; SD, 0.37 years) enrolled in the longitudinal NSW Child Development Study (NSW-CDS), wave 2 linkage.<bold>Main Outcome Measures: </bold>Associations between being the subject of a child protection report (any, and by level of child protection response) during early childhood (birth to 6 years of age) and diagnoses of mental disorders during middle childhood (6-14 years).<bold>Results: </bold>13 796 of 74 462 children in the NSW-CDS (18.5%) had been the subjects of reports to child protection services during early childhood: 1148 children had been placed in out-of-home care at least once, and 1680 had been the subjects of substantiated risk-of-significant-harm reports but were not placed in care, while 9161 had non-substantiated reports, and 1807 had reports of facts that did not reach the threshold for significant harm. After adjusting for sex, socio-economic disadvantage, perinatal complications, and parental mental illness, early childhood contact with protection services was associated with increased frequency of being diagnosed with a mental disorder during middle childhood (adjusted odds ratio [aOR], 2.72; 95% CI, 2.51-2.95). The frequency was highest for children who had been placed in out-of-home care (aOR, 5.25; 95% CI, 4.46-6.18).<bold>Conclusion: </bold>Childhood-onset mental disorders are more frequently diagnosed in children who come to the attention of child protection services during early childhood, particularly in children placed in out-of-home care. [ABSTRACT FROM AUTHOR]