Social relationships and mental wellbeing in autistic adolescent girls and boys: A longitudinal investigation

Abstract Background Previous studies have reported differences in levels of mental wellbeing between autistic and non‐autistic adolescents and between girls and boys. However, it is unclear to what extent being autistic or a particular gender influences mental wellbeing in adolescence. The importance of social relationships for mental wellbeing is well established, but it is unknown to what extent this may differ between autistic and non‐autistic adolescents and between autistic girls and boys. Methods Data from the Millennium Cohort Study were used. Measures of social experience included social support and social alienation at age 14 ( N = 11,056). Mental wellbeing was measured at age 17 ( N = 10,034). Moderated regression analyses after multiple imputation were used to determine (i) whether autism diagnosis moderates the effect of social experience on mental wellbeing and (ii) whether the interaction between gender and autism diagnosis moderates the effect of social experience on mental wellbeing ( N = 16,370). Results In this nationally representative sample, levels of mental wellbeing are lower for autistic adolescents and for girls. Autistic girls had the lowest wellbeing, with large differences relative to non‐autistic boys (mean difference: −3.09; 95% CI: −4.565, −1.612) and non‐autistic girls (mean difference: −1.66; 95% CI: −3.13, −0.180). Autistic boys had lower wellbeing compared to non‐autistic boys (mean difference: −1.68; 95% CI: −2.54, −0.824) and non‐autistic girls (mean difference: −1.43; 95% CI: −1.69, −1.18). Autism does not moderate the effect of social experiences on mental wellbeing. No moderations were found on the effect of social experiences on mental wellbeing when all potential interactions are considered. Conclusion Social support and social alienation during early adolescence equally impact the mental wellbeing of autistic and non‐autistic individuals at later adolescence. Considering the low mental wellbeing of autistic adolescents, there is a critical need to improve their social experiences.