The Role of Peer Victimisation and Parental Mental Health in Internalising Problems: Examining Bidirectional Relationships Across Childhood and Adolescence in Autistic Youth

Purpose Anxiety and depression (‘internalising symptoms’) are common in autistic children and young people. For non-autistic youth, there are reciprocal relationships between internalising difficulties and parental mental health and peer victimisation, but it is unclear whether this holds for their autistic peers. This study investigates longitudinal and bidirectional relationships of parental mental health and peer victimisation with internalising symptoms in autistic children and young people. Methods Autistic children and young people in the Millennium Cohort Study ( N = 560) were included. Measures were parent-reported. Random-Intercept Cross-Lagged Panel Models (RI-CLPMs) were estimated to examine bidirectional associations of internalising symptoms with parental mental health and peer victimisation across six timepoints (3- to 17-years-old). Results Both the RI-CLPM of child internalising symptoms with parental mental health, and with peer victimisation, revealed autoregressive paths across timepoints. Greater peer victimisation at 5-years predicted greater internalising symptoms at 7-years, and these associations were unchanged after accounting for covariates. Parental mental health at 3- and 5-years predicted internalising symptoms at 5- and 7-years, and conversely, internalising symptoms at 14-years predicted greater parental mental health difficulties at 17-years. However, associations between parent mental health and internalising were attenuated after adjusting for covariates. Conclusions Peer victimisation may contribute to the development of internalising symptoms in autistic children from a young age. Targeting interventions for environmental factors may be a means to promote better mental health for young autistic people.