Children with autism spectrum disorder (ASD) have shown high variability in learning outcomes in response to evidence-based interventions, suggesting a need for individualization of intervention programmes for each child and his/her family. To explain this variability and develop effective intervention strategies research suggested focusing on identification of important contextual factors that might influence the effectiveness of a specific intervention for each child such as family cultural characteristics and characteristics of service settings and systems. The overarching aim of the thesis was to identify and describe proximal and distal environmental factors and processes affecting implementation and provision of interventions and services for young children with ASD and their families within the context of the Swedish support system. Two theoretical models guided the research project: Bronfenbrenner’s bioecological model of human development and Wachs’s multiple-influences model of individual variability. The specific objectives addressed using a mixture of qualitative and quantitative methods were: (i) to investigate the scope of reporting ethnicity and other cultural factors in research publications by Swedish scholars involved in empirical research in ASD in children and youth (Study 1); (ii) to explore perceptions of autism, beliefs about its causes, and treatment preferences expressed by parents of children with ASD from culturally, ethnically and linguistically diverse backgrounds (Study 2), and (iii) to explore grandparents’ perceived needs in relation to having a young grandchild with ASD (Study 3).

The results of data triangulation across the three studies showed that within the context of the Swedish support system, three proximal environmental factors were associated with identification of ASD in young children and families’ use of services and interventions before and after the child was diagnosed with ASD. These were parents’ belief systems (including perceptions about child’s autism, help-seeking behaviours, and treatment preferences); the role of preschool teachers, and the role of other service providers, such as healthcare professionals. Data triangulation singled out seven groups of distal environmental factors: beliefs of extended family; family cultural, ethnic and linguistic background; family socio-economic characteristics (occupation and education level); Swedish formal support system enacted through various legislative acts; international laws and regulations; information sources (mass media and social media), and conceptualization and clinical definition of ASD (as reflected in DSM and ICD classifications). Findings also highlight the importance of taking into consideration of role of ASD researchers as an additional distal environmental factor affecting implementation of interventions and services for culturally and linguistically diverse children with ASD and their families.

The results of the studies provide insights into understanding of families’ belief systems about ASD causes, treatment preferences, and needs that are essential for planning and provision of family-level early interventions for children with ASD in the cultural context of Sweden. Implications for practice and future research are discussed.