Associations between self-reported and agency-reported child maltreatment and mental illness in later life: Results from the CALM study

Background: Child maltreatment (CM), including physical, emotional, and sexual abuse, and neglect, has been consistently linked to various mental illnesses. Research directly comparing self-reported versus agency-reported CM, however, is limited, especially with official mental health services use. Objectives: This study compared associations between hospital admissions and community mental health service use for mental illness in self-reported versus agency-reported CM. Participants and setting: Agency-reported CM from 0 to 15 years was linked to an Australian birth cohort via administrative record linkage, and self-reported CM was collected at 30-year follow-up. Results: The sample included 2392 individuals. Self-reported CM was significantly associated with admissions for any type of mental illness (ORadj = 2.84, 95%CI 1.95-4.13), psychotic disorders (ORadj = 3.26, 95%CI 1.79-5.95), and common mental disorders (ORadj = 3.38, 95%CI 2.13-5.36), as well as increased community mental health service use (ORadj = 3.66, 95%CI 2.43-5.52). Agency-reported CM was only associated with admissions for any type of mental illness (ORadj = 2.36, 95%CI 1.32-4.21), and increased community mental health service use (ORadj = 2.91, 95%CI 1.62-5.25). Conclusion: Self-reported CM showed higher effect sizes with higher degrees of certainty with all forms of mental illness service use compared to agency-reported CM, highlighting the need to consider both in future research.