Mental Health, Bangladesh) for their support in data collection. They always gave me valuable suggestions how to build up ideas regarding the context of low middle-income countries. I am also grateful to Dr. Nabiul Islam Khan, (Professor, Forestry and Wood Technology Discipline at Khulna University, Bangladesh) for sharing knowledge of 'R' package.I am thankful to the research assistants in Bangladesh (Mst. Fasmaun and Mahjabeen ara) and Maryam Hakim in Germany who helped me to collect data from Bangladesh and Germany. I am particularly grateful to all participants of this study (Mental Health Professionals and special teachers working with children with autism in Bangladesh and Germany) who spent time for the research survey. Finally, I would like to give a heartiest thanks to my beloved husband, Md. Faisal Abedin Khan for his every support and encouragement to fulfil my dreams. Last but not least, I want to give a big hug to my son Rami, who was in Germany during my study period and always gave me unconditional love and inspiration. I am extremely grateful to my entire family for their love, patience, support, and blessings. Without them I would not have been this position today. Thank you all! iii healthcare systems of Bangladesh and Germany are described as well as the organizations that provide services for children and adolescents with ASD. The terms "Evidence-based practice (EBP)" and "Evidence-based practices (EBPs)" are defined. Then, attitudes towards EBP and EBPs as well as what are the barriers and facilitators to the implementation and usage of EBP and EBPs are described. Respective theoretical models are presented. Next, goals, research questions, and basic structure of this dissertation are presented in this chapter. Finally, short summary of the three studies of this dissertation are presented. Chapter 2 presents Paper 1-Pervin, M., Ahmed, H. U., & Hagmayer, Y. (2022). Effectiveness of interventions for children and adolescents with autism spectrum disorder in highv income vs. lower middle-income countries: An overview of systematic reviews and research papers from LMIC. Frontiers in Psychiatry, 13.