Internalizing Problems as a Mediator for Quality of Life in Emerging Adults with and without Autism. A 10- year longitudinal study

Background: Individuals with autism tend to have a reduced quality of life across the lifespan. This reduced quality of life is a result of autism traits, mental distress, and poor person/environment fit. In the present study, we examined the mediating role of internalizing and externalizing problems on the relationship between having an autism diagnosis and perceived quality of life in a longitudinal design. Methods There were in total 66 participants in a combined group of emerging adults diagnosed with autism spectrum disorder (mean age 22.2 years), and a group without autism (mean age 20.9 years) prospectively followed for ten years through three assessment waves at 12, 14 and 22 years. Participants filled out the Perceived Quality of Life Questionnaire. Total and indirect effects were tested in serial mediation analysis. Results Results revealed a significant effect of autism on quality of life. Internalizing problems at two-year follow-up significantly mediated quality of life in emerging adulthood while externalizing problems did not. The direct effect of autism on quality of life did not reach statistical significance after entering internalizing problems as a mediator. Conclusion There is a significant correlation between having autism and poor quality of life; however, this correlation is mediated by adolescent internalizing problems' impact on the current perceived quality of life.