Children with experience of maltreatment, abuse or neglect are known to have a higher prevalence of poor mental health. Child Protection Services identify children most at risk of harm and in need of intervention. Mental healthcare usage in this population is not well understood as registration data is not routinely linked to health records. We undertook data linkage to describe the population on the register, their mental healthcare usage and to calculate age- and sex-specific incidence rates of mental health outcomes. We analysed records from the Aberdeen City Council Child Protection Register and for mental health prescribing and referrals to child and adolescent mental health services (CAMHS) for the NHS Grampian region between 1st January 2012 and 31st December 2022. We identified 1,498 individuals with a Child Protection Register registration, of which 70% were successfully matched to health records. 20% of registrations occurred before birth and the median age of registration was 3 years. 10.1% of children with a registration ever received a mental health prescription, 5.1% for treatment of attention deficit hyperactivity disorder and 1.7% for treatment of depression. 18.9% received a referral to specialist outpatient Child and Adolescent Mental Health Services. Age- and sex- standardised incidence rates for mental health prescribing and referrals are higher for children with a child protection registration compared to the general population. Children identified as being at significant risk of harm and involved with child protection services are at greater risk of seeking or receiving professional mental health support than their peers. Clinical services should investigate additional ways to support this population’s mental well-being as a priority. Efforts to reduce the exposure of children to potentially harmful environments at a societal level should also be pursued
